A history of ASA standards

The Acoustical Society of America (ASA) was founded in 1929 and immediately set about the business of holding meetings, publishing an archival journal, and sponsoring the development of standards on acoustics. A Committee on Acoustical Standardization was appointed at the meeting held in Chicago in December 1929.

Work on the development of standards is at the core of fulfilling the portion of ASA's mission statement that calls for promoting the practical application of acoustics. In those early decades, the members of the ASA Executive Council reviewed and approved every standard developed by the committees ASA sponsored before it could be published.

Eventually, as the Society grew and the number of standards being developed or revised multiplied, the Executive Council delegated some of this responsibility to a Standards Advisor. In 1970, ASA established the ASA Committee on Standards (ASACOS), led by the Standards Director who is an ex officio member of the Executive Council. ASA's Rules specify that ASACOS is “Charged with setting policy and managing the activities of the Society which support the development and publication of standards on acoustical subjects.”

ASACOS was, and continues to be, an important conduit to disseminate knowledge in the field of acoustics and vibration to users in industry, government, and academia. Within ASA, the members of ASACOS provide a link from each ASA Technical Committee to the standards developing committees, both national and international.

The achievement of this part of ASA's mission would not be possible without the dedication of volunteers—many hundreds of men and women through the years—who have devoted countless hours of time and many miles of travel to work on standardization projects in their areas of expertise. At any given time, there are scores of active working groups working in virtually every area of acoustics and vibration. As shown in the pages that follow, ASA's Standards Program has benefited from participation by many of ASA's most distinguished members. In fact, only a few of the key leaders are mentioned in this paper. Scores of Committee, Technical Advisory Group, and Working Group Chairs have served since 1929 who are not recognized here simply because it would be beyond the scope of this brief history. Nevertheless, we are indebted to them all for their contributions, dedication, and leadership.

The ASA held its first meeting in May 1929. In December of that year, the Executive Council established a Committee on Acoustical Standardization. At the ASA meeting dated 31 December 1930, ASA President Harvey Fletcher presented the report of the “Committee on Acoustical Standardization” consisting of 38 typewritten pages of definitions. The committee, chaired by Halsey A. Frederick, was authorized to continue its work with the plan to publish its report in the Journal of the Acoustical Society of America (JASA) to invite opinions and criticism from members of the Society. This report appeared in January 1931.¹ 

In November 1931, ASA's President, Dayton Miller, appointed a committee on “Standard Methods of Measuring Noise, Coefficients of Sound Absorption and Coefficients of Sound Transmission.” This committee was chaired by Vern O. Knudsen (Fig. 1). Among other tasks, they set out to identify other societies that were working on similar projects.

By 1932, Knudsen had been asked by the American Standards Association [now the American National Standards Institute (ANSI)] to chair a committee on “Measurement of Noise.” The American Standards Association also had a committee working on acoustical terminology. Knudsen proposed turning over the work done by his committee to expedite the work of the American Standards Association. He also wanted to expand the scope of the American Standards Association committee to align with the scope of ASA's work (i.e., add the work related to coefficients of sound absorption and sound transmission).

Knudsen became President of ASA in 1933. By that time, the American Standards Association Sectional Committee on Acoustical Measurements and Terminology (Z24) was sponsored by the ASA. The “Z24” designation was assigned by the American Standards Association. Standards developed by this group would carry that designation until the 1960s.

This relationship with ASA as the sponsor of work conducted by the American Standards Association continued for many years with minor procedural changes over time. Generally speaking, the Sectional Committee comprised subject-matter experts representing the societies that were stakeholders. A draft standard was balloted within the Sectional Committee, and when consensus was achieved it was transmitted to the Sponsor for its approval. During this time the ASA Executive Council (EC) voted on the approval of each standard under its sponsorship. Upon approval by the ASA Executive Council, the draft standard was returned to the American Standards Association for its final approval.

Work on the most basic standards was of great interest to the ASA and early draft standards were published in JASA to solicit comments from the members. “Proposed Standards for Noise Measurement”² appeared in 1933 and would later become Z24.2-1936 which also appeared in JASA. Early drafts of this standard were also published in “numerous trade and technical publications for comment and criticism”³ before final approval.

By 1935, the Executive Council approved tentative standards on Noise Measurement (Z24.2) and Sound Level Meters (Z24.3) and sent them back to the American Standards Association for final approval. Z24.1: Acoustical Terminology was approved in 1936,⁴ along with Z24.2-1936: American Tentative Standards for Noise Measurement³ and Z24.3-1936: American Tentative Standards for Sound Level Meters.”⁵ These first three standards, at least, were published in JASA. Z24.4: American Recommended Practice in the Calibration of Microphones was approved in 1937.⁶ Additional information about the history of sound level meter standards and the long perpetuation of different standards in the U.S. and the Americas vs those in Europe and Asia can be found in Sec. IX.

The ASA Executive Council also actively oversaw the appointment of ASA representatives to other Sectional Committees such as Z10, “Letter Symbols and Abbreviations for Science and Engineering,” as well as numerous other committees on other topics of interest. The current version of this standard exists today as two IEEE standards: IEEE 260.1⁷ and IEEE 260.4.⁸ (The WG for the 2018 revision of IEEE 260.4 consisted almost entirely of ASA members.)

Work in Z24 continued primarily in topics related to instrumentation and measurement until the scope of Z24 was expanded in 1942 to include mechanical vibration:

Early standards were being revised as new information became available and new topics arose regularly. Executive Council members were responsible to approve each standard and they sometimes raised technical objections sending the work back to the Sectional Committee.

In 1946, Leo Beranek prepared a report to the Executive Council proposing a plan to increase ASA's representation on Z24 and to establish terms for ASA's members of Z24. In this report, he noted that Knudsen had been serving as Chair of Z24 since 1930—16 years—and it was proposed to reappoint him for another 4-year term. He also proposed that ASA become, for the first time, an Associate Member of the American Standards Association.

Z24's work had expanded to include six subcommittees:

1. Terminology, Charles F. Wiebusch, Chair,

2. Fundamental Sound Measurements, Leo L. Beranek, Chair,

3. Noise Measurement and Sound Level Meters, C. J. G. Gray, Chair,

4. Sound Absorption and Sound Insulation Measurements, Richard H. Bolt, Chair,

5. Audiometry and Hearing Aids, Richard K. Cook, Chair (see Sec. X),

6. Underwater Sound Measurements, Robert S. Shankland, Chair.

As the activity related to standardization increased, the Executive Council found it more difficult to ensure that they had sufficient communication with Z24. In 1947, they established an ASA Standards Committee to keep in touch with all the “standards problems that the Society is or should be interested in.”

This committee was chaired by Leo L. Beranek (Fig. 2) and included Laurence Batchelder, Vern O. Knudsen, Joseph C. R. Licklider, R. Bruce Lindsay, Kerron Morrical, Frank F. Romanow, Robert S. Shankland, and Charles F. Wiebusch. One of the tasks delegated to the Standards Committee was to review the standards approved by Z24 and make recommendations for approval to the Executive Council.

In 1949, Keron C. Morrical was named Chair of the Acoustical Society of America's Standards Committee. He replaced Beranek, who became Vice Chair of Z24 at that time and ascended to Z24 Chair in 1950, replacing Knudsen who had served for 20 years.

In 1950, the Executive Council decided that there was no need for a Standards Committee; instead they named Morrical as ASA's “Standards Advisor” and left it to him to establish ad hoc committees to assist him as needed. He became responsible for making recommendations to the Executive Council to approve or disapprove standards prepared by Z24.

In 1951, Morrical became chair of Z24, with Frank F. Romanow as Vice Chair and ASA Standards Advisor. Later that year, Morrical died, and Beranek resumed as chair of Z24. In 1952, Beranek was named Standards Advisor for the Acoustical Society and Laurence Batchelder became Vice Chair of Z24. Robert W. Young was named one of ASA's representatives to Z24.

The scope of Z24 was again expanded by the American Standards Association's Electrical Standards Board in 1953 to include elements related to human factors:

This change permitted the introduction of a new exploratory group entitled “Bio- and Psycho-Acoustic Criteria for Noise Control (Z24-X-2)” which included work on ultrasonic acoustic output. This exploratory group ultimately published a report “The Relations of Hearing Loss to Noise Exposure” (January 1954).

Laurence Batchelder (Fig. 3) became Chair of Z24 and Standards Advisor in 1953. Batchelder's first report to the Executive Council noted that Z24 had by then 23 active writing projects and the administrative burden was increasing. In 1953, he noted the growth of activity in the newly established committee, International Electrotechnical Commission Technical Committee IEC TC 29, Electroacoustics, and International Organization for Standardization ISO/TC 43, Acoustics. He sought guidance from the Executive Council as to how Z24 should interact with these international organizations. By the next year, Z24 was acting as a Technical Advisory Group in regard to IEC TC 29, reviewing international documents and advising the newly established Acoustical Standards Board of the American Standards Association on its vote.

The back page of Z24.X2 showing a list of Z24 standards available in the mid-1950s is shown in Fig. 4.

Z24's growing body of work on vibration required coordination with the American Society of Mechanical Engineers (ASME) which was co-sponsor, with ASA, of the vibration work. All vibration standards not only had to be approved by the ASA's Executive Council, they also had to be reviewed and approved by the ASME Applied Mechanics Division. By 1954, there was a strong feeling that Z24 was too big and too cumbersome. Robert W. Young proposed splitting the committee into several parts and giving the work over to sponsorship by other organizations. Although this was discussed for some time, there was no strong support for it and ASA remained the sponsor. To help facilitate the involvement of experts from the vibration and shock community, a special meeting of Z24, focused entirely on shock and vibration, was conducted in 1955 in coordination with ASME and the Society for Experimental Stress Analysis. The issue of trying to find the “right” home for the development of mechanical vibration and shock standards continued for many years (see Sec. VI).

Beranek became Chair of the American Standards Association's Acoustical Standards Board (ASB) and began to reorganize Z24. By 1956, the ASB divided Z24 into three Sectional Committees:

• S1 Acoustics

• S2 Mechanical Vibration and Shock

• S3 Bio-Acoustics

The Acoustical Society of America was asked to serve as sponsor of all three committees and agreed to do so (with ASME continuing as co-sponsor for vibration). Batchelder remained as Chair of Z24 during the transition and also as Standards Advisor until 1957 when he was succeeded by Arnold P. G. Peterson as Standards Advisor.

From 1930 until 1957, the American Standards Association served as the Secretariat of Z24 with little or no financial input from ASA. Upon the formation of three new Sectional Committees, the American Standards Association notified ASA that it could no longer provide this level of service. They asked ASA to contribute $3500 per year to support this work and this was approved by the Executive Council, with ASA designating revenue from the Society's sustaining membership program to cover this expense. Although ASME remained co-sponsor of S2, it did not share the financial burden. This was an issue that ASA strove to rectify many times over the years culminating in 1974 when the matter was finally resolved through the appeals process at the American Standards Association. (see Sec. VI).

Peterson was succeeded as Standards Advisor in 1959 by Horace M. Trent. The issue of financing the support of standards work continued to be of concern. Repeated efforts to obtain support from ASME for S2 failed. Instead, ASME began to suggest that it should take over S2 entirely. However, leaders in the ASA and S2 felt that ASME's technical input in regard to S2's work was actually minimal. ASME did provide meeting space for one of S2's meetings per year and the chairmanship of S2 rotated between ASA and ASME.

Throughout the 1960s, the ASA Executive Council continued to approve individual standards already approved by the standards committees, ASA input on acoustical standards developed by other organizations, and the appointment of new members of each of the standards committees. Because acoustics was of interest in many organizations, there continued to be a good deal of need for cooperation among organizations. In 1961, the Acoustical Standards Board became concerned about the lack of conformity in regard to terminology and created a Terminology Panel which developed guidance for standards writers.

In 1961, the Acoustical Standards Board considered if the Institute of Environmental Sciences and Technology (IEST) should replace ASME as co-sponsor of S2 but nothing came of this.

The Minutes of the ASA Executive Council make it clear that from the mid-1950s, members of Z24 had also served as the Technical Advisory Group to IEC TC 29, Electroacoustics. ISO TC 43, Acoustics, had been established in 1947 and presumably Z24 also provided the U.S. input for its standards. (See Sec. XI.) By the early 1960s work in ISO and IEC was beginning to engage more interest in the U.S. ASA members were engaged in IEC TC 29 and ISO TC 43 but there was no international counterpart to S2, Mechanical Vibration and Shock.

By 1962, Douglas F. Muster (Fig. 5) became chair of the S2 working group on balancing of rotating machinery and immediately engaged with his international colleagues on this subject. The ASA Executive Council's minutes of May 1962 noted that, at that time, no international organization was prepared to sponsor work on balancing of rotating machinery. The IEC recognized that the work had no electrical or electronic component and the ISO said that it had no committee having mechanical vibration and shock within its scope. Thus began consideration of a plan to propose the formation of a new ISO committee. It was recognized that if the American Standards Association put forth such a proposal, it would need to be prepared to serve as the secretariat at a cost of about $5000 per year. There was also concern that S2 would lose its position as world leader in regard to vibration and shock standards. On the other hand, they recognized that Germany seemed poised to take this step if the U.S. did not. United States Navy support was obtained and the U.S. submitted the proposal.

In 1963, Trent asked to be replaced as Standards Advisor, and Frederick V. Hunt (Fig. 6) was appointed. By this point it was certain that the U.S. would have the secretariat of the new ISO Technical Committee ISO TC 108, Mechanical vibration and shock.

The first plenary meeting of ISO TC 108 was held in Aix-les-Bains, France, in June 1964 with the American Standards Association serving as Secretariat and Trent as chair. The scope of the new committee was established.

Standardization in the field of mechanical vibration and shock, including:

• Excitation by sources, such as machines and vibration and shock testing devices.

• Elimination, reduction and control, especially by balancing, isolation, and damping.

• Evaluation of acceptable limits for man, and in machines, vehicles, and structures.

• Methods and means of measurement and calibration.

• Methods of testing (liaison with other ISO and IEC committees as required, where applicable).

• Terminology.

More information about the history of ISO/TC 108 is provided in Sec. XII.

Work continued on myriad standards in each of the committees, some moving along smoothly and some creating turmoil. In 1963–64, the proposed revision of the S3 audiometer standard in regard to the reference threshold of hearing created quite a stir which reached the ASA Executive Council.

In 1965, Hunt resigned as Standards Advisor and Batchelder resumed that role.

In 1966, the American Standards Association rebranded itself as the USA Standards Institute (USASI). But this new name did not change its operations in regard to the three standards committees sponsored by ASA. ASA was still contributing $3500 per year to fund the Secretariat's services, unchanged since 1957. The leadership of the standards committees and ASA felt that the committees needed more support than they were receiving from the Secretariat. The ASA Executive Council set up an ad hoc committee “Procedures for Domestic Standardization and USA Participation in International Standardization” consisting of the chairs of the S-committees; the Technical Advisors to ISO TC 43, ISO TC 108, and IEC TC 29; the chair of the USASI Acoustical Standards Board; the ASA Standards Advisor; the ASA President-elect; and the Secretary of the Acoustical Society of America, acting as chair. This structure is the precursor to the current ASA Committee on Standards (ASACOS). By 1968, USASI increased the fee for Secretariat services to $7500 and the ad hoc committee made the recommendation that ASA should take this work in-house instead. (See Sec. XXI.) In 1969, Avril Brenig (Fig. 7) joined the ASA staff as a part-time secretary to support S1, S2, and S3. In 1978 the Executive Council chose a new structure to develop standards under the auspices of the Society. In addition to an appointed Standards Director, the Standards Secretariat was established with Avril Brenig as the first Standards Manager in order to oversee the operational activities of the growing standards organization. Brenig continued to serve in that position until her retirement in 2000.

Changes continued within USASI, including the establishment of the Board of Standards Review (BSR) which would approve all standards rather than having them approved by standards boards within each subject area. By 1969, USASI again rebranded itself, becoming the American National Standards Institute, or ANSI, as we know it today.

In 1970–71, the ASA Committee on Standards (ASACOS) was formed with Batchelder as Chair and Standards Advisor. The ASA Executive Council delegated its responsibility to give ASA's approval on American National Standards to ASACOS. Over the next few meetings, the Executive Council worked to spell out the responsibilities and membership of ASACOS.

One concern of ASACOS members in the early years was how they were to vote on standards submitted to ASACOS for approval in the name of ASA. These documents had been developed by working groups of subject-matter experts and had already gone to the relevant S-Committee for approval and also to ANSI's Acoustical Technical Advisory Board (ATAB), successor to Acoustical Standards Board. They were subsequently submitted to ASACOS for ASA's approval before going to ANSI for its final approval. Since ASACOS's members are drawn from the diverse technical membership of ASA, some felt uncomfortable being asked to approve documents outside their technical areas. Some felt their approval was more procedural than technical. By the late 1970s, it seems that they settled into a more comfortable process of approving standards by ballot between meetings.

A lot of ASACOS's time was, and continues to be, devoted to developing procedures and policies both for the development of American National Standards under the S-Committees administered by ASA and to fulfill ANSI requirements, as well as related procedures and policies such as the Editorial Rules. ASACOS also was responsible for the development of an ASA position on standards developed by other Standards Developing Organizations (SDO) with which ASA liaised.

Between 1972 and 1974, ASACOS studied the idea of publishing the standards produced by its standards committees rather than allowing ANSI to do this, as it had always done. (See Sec. XXII.)

Over the years, ANSI's policies and requirements changed and ASA was required to align with those changes. In 1978, an Office of Management and Budget Circular raised questions about the status of the many Standards Developing Organizations and Committees in the very much decentralized U.S. standards systems. Who, it asked, was responsible for the standards developed—and who was legally liable for any problems arising from them? ANSI, itself, is not a Standards Developing Organization but rather is a non-governmental organization that coordinates the development of standards in the U.S. It became clear that ANSI needed to clarify its relationship to the organizations and committees in its federation—to make it clear that a committee developing American National Standards is not an “ANSI Committee” and that ANSI's approval of a standard represents assurance that it has been developed under a given process, not that ANSI has approved the technical content. The push for ANSI member organizations to become accredited by ANSI began.

Henning von Gierke (Fig. 8) succeeded Batchelder as Standards Advisor and Chair of ASACOS in 1973. In 1978, his title was changed to Standards Director and the Standards Director became an ex officio member of the ASA Executive Council.

von Gierke's leadership in research regarding human exposure to noise and vibration was translated into national and international standards work via his role as Chair of S3, Chair of the U.S. Technical Advisory Groups to ISO TC 43 Acoustics, ISO TC 43/SC 1 Noise, and ISO TC 108/SC 4 Human exposure to mechanical vibration and shock, for which he served as chair for 30 years. He also participated in and chaired the National Research Council Committee on Hearing, Bioacoustics, and Biomechanics (CHABA). Many of the scientists who worked for von Gierke later assumed leadership roles in the ASA Standards program, including Daniel Johnson, Alice Suter, and Richard McKinley, among many others.

During von Gierke's tenure as Standards Director, interest in the subject of noise dominated and the number of joint work items between S1 (physical acoustics) and S3 (bioacoustics) grew rapidly. To avoid conflict and difficulty in assigning work between the two committees, a joint S1/S3 committee was formed in 1970 and continued meeting at each ASA meeting until it was terminated in 1981 when S12 was established.

In 1971, ASA was asked to vote, under the canvass method, on a draft standard proposed by Association of Home Appliance Manufacturers (AHAM) concerning sound rating of room air conditioners. The ASA voted no, principally objecting to the proliferation of noise rating scales such as the one proposed by AHAM. The ASA Executive Council voted to draft a standard in the area of home appliance measurement and allocated funds for a conference on noise standards.

A task force was established, chaired by William Lang, then chair of S1, and the 4-day conference was hosted by IBM at Arden House in NY. The main charge to the task force was to provide a noise standard for home appliances and other consumer products. It resulted in two draft standards on measurement and rating of home appliance noise and three recommendations: Policies and Requirements; Organization and Operations; Publications and Interrelationships.

The drafts were balloted in S1 and S3. The measurement standard S1.21-1972 Standard Methods for the Determination of Sound Power Levels of Small Noise Sources in Reverberation Rooms, was approved by S1. The draft for rating the sound power spectra of small stationary noise sources (S3.17-197x) failed in S3 in 1972.

The task force was disbanded in April 1972, not having achieved its goal of providing a standard that would be better than the proposed AHAM draft. The joint S1/S3 group voted 13 to 11, to recommend that the ASA Executive Council withdraw its negative vote on the AHAM standard. Eventually, the rating of sound power spectra standard S3.17 was finally approved in 1975.

Nevertheless, the three recommendation documents were useful in helping clarify the role of the newly established ASACOS and its relationship to ANSI, the S-Committees and the working groups.

In 1976, ANSI formed an Environmental Noise Planning Panel to assist regulatory agencies in regard to noise issues. Initially this Panel was formed without input from the Acoustical Standards Management Board (ASMB) but ultimately, Kenneth M. Eldred (Fig. 9), then chair of ASMB, was also named chair of the Panel.

In December 1977, ASA organized a Workshop on Environmental Sound with funding from the U.S. Environmental Protection Agency (EPA). This was a meeting of regulatory agencies and non-governmental organizations (many of them were also members of the Environmental Noise Planning Panel). Its goal was to develop plans and guidelines, define the scopes of needed standards, and identify research needs and knowledge gaps.

In 1979, when von Gierke became President of ASA, William Galloway (Fig. 10) became Standards Director

During Galloway's term, the new ASA S-Committee, S12 Noise, was approved by ANSI on September 30, 1981. It has grown over the years to be the largest of the four ASA S-Committees and is responsible for the largest number of standards.

By 1982, ASACOS was no longer voting to approve standards. The authority for approving the technical content of a standard was agreed to rest solely with the respective S-Committee. The so-called “final approval” from ANSI represents its approval to use the “ANSI” designation and its assurance that the standard was developed and approved according to ANSI-accredited operating procedures. ASA's Standards Committee Operating Procedures were accredited by ANSI for the first time in 1983. ASA has maintained its status as an ANSI-Accredited Standards Developing Organization ever since.

Beginning in the late 1990s, ANSI instituted a requirement for ANSI-Accredited Standards Developing Organizations to undergo a five-year program audit to maintain accreditation. ASA has had four successful audits to date, the most recent in 2013.

In 1983, William Melnick (Fig. 11) became Standards Director, followed by Kenneth Eldred in 1987.

In 1984, ANSI issued Model ISO Technical Advisory Group (TAG) Operating Procedures for the first time. ASA adopted TAG Procedures closely tracking the model with modifications to follow the canvass procedure ASA had been using, which is essentially the same as today. In 1986, ASA submitted its ISO TAG Procedures for ANSI accreditation, which was granted on 17 April 1989 and has been continuously maintained. In 1994, ANSI implemented a requirement for an annual report from each ANSI-Accredited U.S. TAG to an ISO committee or subcommittee. It was not until 2002 that formal procedures were required for the IEC TAGs and the U.S. National Committee (USNC) to the IEC, a division of ANSI, who then promulgated its own model procedures. Again, ASA adapted those model procedures to ensure that the ISO and IEC TAGs are operated in the same manner. The USNC does not accredit its TAGs but rather refers to them as “USNC approved.”

The role of the U.S. Technical Advisory Group (TAG) is to review drafts of international standards arising from either ISO or IEC and develop the U.S. voting position and comments. The vote is officially submitted by ANSI based on the recommendation of the TAG. Members of the U.S. TAG serve as members of the international working groups and attend international meetings as official members of the U.S. (ANSI) delegation.

By the late 1980s the role of ANSI's Acoustical Standards Board (ASB) had diminished to the point that ANSI considered dissolution due to low attendance. Henning von Gierke, who was then chair, decided to maintain the committee structure although not call any meetings unless needed. An ad hoc committee was made responsible to monitor things and decide if or when to call a meeting. In 1991, ANSI began to examine the continued utility of its Standards Boards. By 1994, ANSI wanted to eliminate these Boards entirely. The ANSI ASB met in 1994 after not having met for a year. They discussed disbanding and various options to continue without ANSI. In the end, the Board asked ANSI to allow it to continue. ANSI reluctantly agreed, but insisted that the Board meet at least once a year, submit an annual report, and also submit an annual registration list. In 1996, Richard Peppin became chair of the board, by then called the Acoustical and Vibration Standards Board (AVSB). This continued until the end of 1997 when ANSI disbanded the Standards Boards as a cost-saving measure. The members at the time expressed some enthusiasm to maintain the board but were unwilling to pay ANSI to do this. ASACOS considered assuming leadership to continue this activity but eventually this was abandoned.

In the early years, ASACOS approved each new organizational member of each S-Committee as the ASA Executive Council had done before. By 1990, the S-committees were approving applications for membership via letter ballot. In 2003, Peppin proposed elimination of this requirement. He argued that since the only prerequisite for S-Committee membership is having a “direct and material interest” in the work of the committee, there were no criteria to support a negative vote on a prospective member. In fact, the only reason to reject a member would be if the addition of a new member would create an imbalance among the interest categories. With the approval of all four S-Committees, the Procedures were revised. Applications for organizational membership are now reviewed by the Standards Manager and the Committee and/or TAG chair and are automatically approved unless such approval would create an imbalance. Any application rejected by the Standards Manager must be submitted to the Committee for final decision.

Administration of the committees became increasingly complex and ASACOS tried to ensure that a reasonable plan was in place to ensure timely action to reaffirm, revise, or withdraw existing standards to avoid their administrative withdrawal by ANSI. In 1991, the Chair and Vice Chair of each S-Committee were charged with the task to monitor the committee's work program and make recommendations. The S-Committees were asked to develop three-year business plans for discussion at each ASACOS meeting.

In 1990, ASA hired Charles E. Schmid as its first Executive Director, succeeding Murray Strasberg who had served as Secretary of ASA since 1987. As Executive Director, Schmid shared responsibility with the Standards Director for overseeing the Standards Manager and the functioning of the Standards office.

In 1993, Tony F. W. Embleton (Fig. 12) was named Standards Director and Chair of ASACOS. He had previously served as chair of S1 from 1982 to 1985. Embleton's scientific research focused primarily on noise control, outdoor sound propagation, and community noise.

Embleton recalls that during his tenure as Standards Director, the Standards Program experienced considerable financial pressure and the Executive Council gave serious consideration to abolishing it entirely. He devoted significant effort to administrative matters such as making the value of the Standards Program, both to ASA and to the general public, visible to those members of the Executive Council who were not closely involved with standards.⁹ He stressed the direct links between specific standards and the ASA Technical Committees. He also developed estimates of the number of ASA meeting attendees whose primary reason for attending involved participation in standards work. Embleton believes that his own credibility as past President of ASA helped to ensure the continuation of the Program.

As the Standards Program became bigger, ASACOS worked hard to ensure that the S-Committee Operating Procedures were up to date and fair to participants. Policies on issues such as resolving negative comments and handling recirculation ballots, and clarification of the role of Individual Experts, among others, were fine tuned. A Guide for WG Chairs was prepared.

In 1997, Daniel L. Johnson (Fig. 13) became Standards Director and Chair of ASACOS with Paul D. Schomer as Vice Chair of ASACOS.

Prior to being named Standards Director, Johnson served as Chair of both S1 and S12 and was an individual expert in all four Standards Committees. He also chaired or was a member of numerous standards working groups, both national and international. He participated in standards work outside of ASA, including SAE Committee A-21 on Aircraft Noise, ASTM E33 Environmental Acoustics, CHABA working groups, and the ACGIH Physical Agents TLV Committee.

As Standards Director, Johnson took seriously the issues raised during Embleton's term and strove to increase the Standards Program's visibility within ASA. He also worked to try to improve Standards' engagement with the ASA Technical Committees. He implemented the Standards Plenary Group Meeting to discuss topics of broad interest to all the committees so that the same information would not have to be repeated at each S-committee meeting and to address international participation.

Johnson was particularly proud of two standards developed during his term as Standards Director: ANSI S3.1-1999: Maximum Permissible Ambient Noise Levels for Audiometric Test Rooms¹⁰ and ANSI S12.60-2002: American National Standard Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools¹¹ which was published after his death.

During this period, the ASA Standards Program experienced several major transitions including the retirement of long-time Standards Manager, Avril Brenig, recruitment and training of a new Standards Manager, Susan Blaeser (Fig. 14), and relocation of the office to Long Island. (See Sec. XX.)

One technical topic that was of particular importance to Johnson both in his scientific research and in his standards work was understanding the hearing hazard caused by exposure to high-energy impulsive sounds (>140 dB re 20 μPa, A-weighted). He served as Chair of S3/WG 62, Impulse Noise with Respect to Hearing Hazard. After Johnson's death, work continued with James Patterson as S3/WG 62 Chair. In 2004, the WG submitted a draft technical report for ballot which proved too controversial to be approved by S3. The working group found itself unable to move forward, even in regard to making a recommendation on whether or not to disband. In 2006, Patterson polled the group and found them divided. In 2009, with no progress having been made, G. Richard Price volunteered to serve as chair and was appointed to that role. S3/WG 62 is divided concerning several “competing” approaches to this problem, but there is insufficient data to obtain general agreement that one method is the standard. This topic is the subject of ongoing research and frequent technical paper sessions at ASA meetings and the only thing everyone agrees on is that hearing loss will result from exposure to these sounds.

When Johnson died unexpectedly in May 2002, Paul D. Schomer (Fig. 15) was named Standards Director and Chair of ASACOS. Before he became Standards Director, Schomer served as Chair of S12 and Chair of the TAGs to ISO TC 43 and ISO TC 43/SC 1 as well as chairing numerous working groups, both national and international. Since 1983, he has chaired S12/WG 15, Measurement and Evaluation of Outdoor Community Noise, which is responsible for the seven-part S12.9 series on environmental sound. He also was the convener of the parallel ISO working group—ISO TC 43/SC 1/WG 45—for many years.

Schomer stepped down as S12 Chair in 2002 and was replaced by Robert Hellweg, who was also named Vice Chair of ASACOS. Schomer served as Standards Director until his retirement in 2015, the longest-serving Standards Director in ASA's history.

At the time of Johnson's death, ASA was in the midst of fighting American Refrigeration Institute's (ARI) unsuccessful appeal against the classroom acoustics standard (ultimately approved as ANSI S12.60-2002), details of which can be found in Sec. VII. The effort to defend that standard, to revise it in response to experience gained, and to encourage its implementation in the building codes was a great focus for Schomer throughout his tenure.

In 2004, ASACOS approved a restructuring of the standards program under which the U.S. TAGs for ISO or IEC committees were separated from the S-Committees, making it possible for an organizational member to join one or the other independently. Members of the TAGs pay a higher fee and can opt-in to the related S-Committee at no additional cost. Members only of the S-Committee pay slightly less. The rationale was that there is additional cost in maintaining the TAGs and none of that additional cost is offset by the sales of standards as it is for the S-Committees. This also met the stated needs of some members who wanted membership only in the TAG or only in the S-Committee and did not want to be asked to review or vote on documents that were of little interest to them. This structure is still in place today.

Around this time, ASA's President, William Kuperman, suggested that there was a need for a standard for acoustical methods for counting whales. A working group was established in S1 and later moved to S3/SC 1, Animal Bioacoustics, when that subcommittee was established in 2007. (See Sec. VIII.) As with many other topics, the need for a standard on this subject was identified while the topic was—and still is—an active research area. The working group is still active although the title and scope have been refined over the years, now identified as S3/SC 1/WG 3 Towed Array Passive Acoustic Operations for Bioacoustic Applications.

In 2005, ASACOS implemented a new program aimed at making standards available for use in the college classroom. The professor pays a small fee and is granted a license to circulate copies to students in a given class. This has proved to be of most interest in audiology programs although others have used it as well. After ASA began offering free standards to members, including student members in 2007, quite a few professors were able to recommend that students download specific standards of interest in their research area at no fee.

By 2006, S12 received a proposal from Michael Bahtiarian to develop a standard for measuring underwater noise from ships. The goal was to provide a standardized method, based largely on methods long in use by the U.S. Navy, but which did not require the use of a dedicated measurement location. Eliminating the need to bring the ship to a specified location would reduce the cost to ship owners and enable owners to have the measurement performed by any qualified vendor of their choice. S12 approved the proposal and established working group 47 which was met with a surprising enthusiasm, attracting WG members both in the U.S. and from other countries. As work progressed, it became clear that there was sufficient interest to bring this subject into the international arena. ISO TC 43/SC 3, Underwater Acoustics, was formally established in 2011 (see Sec. XV).

One reason for the strong interest in standardization of methods for measuring underwater sound from ships arose from regulatory requirements then being established by government agencies in many countries. The International Maritime Organization (IMO), an agency of the United Nations, was also attempting to establish voluntary ship noise recommendations for the shipping industry. The IMO turned to ISO to seek a measurement standard and ISO looked to ISO TC 8 - Ships and marine technology, to develop such a standard. An overview of the interaction between TC 8 and TC 43 is given in Sec. XVI, later in this document.

Another outside influence leading to the decision to establish TC 43/SC 3 in ISO rather than under an ASA standards committee was the European Union's Marine Strategy Framework Directive, adopted in 2008. This Directive places requirements on the activities of the EU member countries and requires international standards to provide the underpinning to support efforts to achieve its goals.

By 2007, ASA was responsible for about 120 American National Standards, all bearing an alphanumeric designation, e.g., “ANSI S1.4-1983 (R 2006).” ASACOS noted that many other standards developers included their own acronym in the designation which made the relationship between the Standards Developing Organization (SDO) and the document explicit. It was decided to change the designations of standards published by the S-Committees to “ANSI/ASA” to increase ASA's visibility to the public. This was accomplished over the next few years by introducing the new designation when the document was either revised or reaffirmed.

By this time, many International Standards had been nationally adopted by the S-Committees which also had some interest in promoting American National Standards for international adoption. In 2007, the U.S. TAG to ISO TC 43, with the recommendation of S3, proposed the international adoption of ANSI S3.4-2007: American National Standard Procedure for the Computation of Loudness of Steady Sounds¹² to revise and replace the existing ISO Loudness standard. This eventually culminated in an ISO standard published in 2017 based on the methods contained in ANSI S3.4-2007. Detailed information is given in Sec. XVII.

In 2014, ANSI asked ASA to sign new memoranda of understanding regarding the continued administration of the three ISO Secretariats that ASA supported—ISO TC 108, ISO TC 108/SC 5, ISO TC 43, and ISO TC 43/SC 1. This led to a careful review of the three committees and the relative value to ASA of continuing to provide this service. At that time, ASACOS recommended that ASA relinquish the secretariat for ISO TC 108/SC 5 “Condition monitoring and diagnostics of machine systems.” Technically, the work of ISO TC 108/SC 5 has little to do with acoustics or related matters and is far from the heart of ASA. ASA would probably have had nothing to do with this committee except that it was born out of ASA's other committee, ISO TC 108. (Details about the formation of ISO TC 108/SC 5 are provided in Sec. XIII.) Upon learning of ASA's plan, the Vibration Institute offered assistance in a fundraising effort to enable ASA to continue to maintain this secretariat. This fundraising effort proved unsuccessful and ASA moved forward with the plan to relinquish. Administration of ISO TC 108/SC 5 was transitioned to Standards Australia after the ISO TC 108/SC 5 meeting in March 2016.

Schomer began discussing the need of succession planning as early as 2013. When ASACOS accepted the report of the Nominating Committee in October 2014, it marked the first time since Schomer's appointment in 2002 that a new Standards Director was nominated. The Nominating Committee discussed the position with several candidates and nominated Christopher J. Struck, who had previously served as Chair of S3 as well as chair of several working groups. ASACOS unanimously approved the nomination and forwarded it to the ASA Executive Council. Christopher J. Struck (Fig. 16) was named Standards Director and chair of ASACOS upon the retirement of Schomer in 2015. Struck is a consultant specializing in electroacoustical measurements, audio applications, and electroacoustical transducer design.

Struck's tenure as Standards Director started off in 2015 with succession planning for the transition to a new Standards Manager for Blaeser's planned retirement in 2016.

One of Struck's main actions has been implementing technology to make standards more available to the public. For example, he drafted guidelines for software distributed with standards. He also implemented a unified File Transfer Protocol (FTP) Portal for working groups to securely store and share documents. In 2016, encouraged by the EC and the new ASA Strategic Plan, a project was launched by Struck to make the full content of ASA's terminology standards, ANSI/ASA S1.1-2013 Acoustical Terminology¹³ and ANSI/ASA S3.20-2015 Bioacoustical Terminology,¹⁴ available to the public for free online in database format. The result was released in late October of that year and is available free of charge on the ASA website: http://asastandards.org/asa-standard-term-database/.

One problem that has plagued participants of international standards committees, subcommittees and working groups throughout the years has been the lack of travel support for attendance at meetings. A limited amount of support was made available by the R.W. Young Travel Award which provides a small amount of money for participants in IEC TC 29, ISO TC 43, and ISO TC 43/SC 1. In 2017, following the proposal to the ASA EC by Robert Hellweg, Struck was able to obtain additional funding to assist TAG Chairs and others in these committees as well as the others for which ASA administers the TAG.

In 2015, ASA approved its new Strategic Leadership for the Future plan which articulated ASA's purpose as “The purpose of the Society is to generate, disseminate, and promote the knowledge and practical applications of acoustics.” The plan established four high-level goals:

• Awareness of Acoustics.

• Member engagement and diversity.

• Dissemination of information and knowledge.

• Financial stewardship.

Going forward, all decisions and actions are to be aligned with one or more of these goals.

ASA's Standards Program is an outward-facing function of the Acoustical Society, serving and engaging both ASA members and non-members alike. One of the primary activities of ASA Standards is to develop and publish standards that distill practical information about acoustics and vibration and make this information available to users in industry, government, and the academic arenas.

Despite the fact that the Standards Program is engaged in each of the four goals of ASA, one of the lessons learned during the strategic planning process was how little most ASA members actually know about the ASA Standards Program. Leaders within ASA Standards include ASA Presidents, officers, and medal awardees (see Sec. XXIII for more information).

Today, the ASA Standards program comprises four ANSI-Accredited Standards Committees and one Subcommittee, with over 80 Working Groups and approximately 600 volunteer WG members. These committees have published and maintain over 120 American National Standards. ASA also administers 9 U.S. Technical Advisory Committees (TAGs), providing the national input to eight ISO and one IEC committee on topics related to acoustics and vibration. The S-Committees and TAGs are populated by 84 Organizational Members who review and vote on the documents coming before them. Struck, as ASA Standards Director, presented an updated overview of the program at the InterNoise meeting in 2015 in San Francisco entitled “An Overview of the ANSI/ASA Standards Program,”¹⁵ which was subsequently reprinted in Sound and Vibration.

The ASA Committee on Standards (ASACOS) is the body within ASA that governs policy, financing, and program oversight. A Steering Committee handles procedural matters. The voting members of ASACOS include the Chairs and Vice Chairs of each of the Standards Committees, Chairs of the U.S. ISO/IEC Technical Committee TAGs, and representatives from each of the thirteen ASA Technical Committees. ASACOS meets twice a year. Participation by the ASA Technical Committees ensures that members of the technical committees understand standards developments and can communicate the need for developing new standards. There is no requirement for participants in the ASA Standards Program to be ASA members and many are not.

On the international scene, ASA provides the Secretariat for two ISO committees: ISO TC 108, “Mechanical Vibration, Shock and Condition Monitoring” and ISO TC 43/SC 1, Underwater acoustics including their working groups. Figure 17 shows the liaisons between the committees interfacing with the ASA Standards Secretariat.

As mentioned previously, ASME was co-sponsor of S2 from its formation in 1956 and, before that, shared responsibility for vibration and shock standards under Z24. Throughout this time, however, ASME did not share the financial burden of sponsoring S2. Efforts to obtain financial support from ASME continued fairly regularly without success. Things changed when ASME became financially responsible for TC 108.

From the formation of TC 108 in 1964 until 1970, ANSI directly administered the Secretariat of TC 108 funded by a U.S. Navy grant. In 1970 the Navy funding was lost and it appeared that the U.S. would relinquish the Secretariat. At ANSI's request, ASME accepted appointment as Secretariat for ISO TC 108 to keep it in the U.S. This meant that they also assumed the financial responsibility for the TC. At this point, ASME took the position that ISO TC 108 and S2 could be more efficiently administered together than by two separate organizations. They offered in 1970 to take S2, explaining to ASA that they could publish and sell S2's standards to offset the cost of administering both S2 and ISO TC 108. ASA rejected the ASME proposal on the belief that S1, S2, and S3 should stay together.

ASME was seen by ASA to have a substantial standards publishing operation. At this time, standards developed by S1, S2, and S3 were published and sold by ANSI, not by ASA. But this observation that it might be possible to earn money from the sales of standards that could be used to offset the cost of standards development intrigued ASA and they began to explore what it would mean to begin to publish the standards produced by the S-Committees. (See Sec. XXII.)

In 1973, ASME, led largely by Douglas Muster in this endeavor, asked the ATAB (Acoustical Technical Advisory Board), which was then chaired by Batchelder, to reassign lead sponsorship of S2 from ASA to ASME and allow ASME to publish and sell S2's standards. (Although Muster was acting on behalf of ASME in this regard, he was also an ASA member and served as chair of S2 and also chaired TC 108 for many years.) The proposal was discussed at meetings of ASACOS, S2, and the ASA Shock and Vibration Technical Committee, all of which strongly supported ASA's continued management of S2 and, if necessary, they suggested that ASA should take over responsibility for management of the ISO TC 108 Secretariat. There was virtually no information available as to the cost of maintaining an ISO secretariat. Numbers ranging from $6000 to $20 000 were put forward. There was concern that ANSI's policies would prohibit assigning a secretariat to an organization as small as ASA.

As the date of the ATAB meeting approached, ASA's leaders and the leaders of ASA's standards activities actively sought a resolution with ASME. ASME was increasingly clear that they needed the revenue from S2 to support TC 108, so it was proposed that they be given the publication rights to S2's standards. Although this plan would seem to have provided the sought-after revenue, it was not accepted. ASA then sought estimates of the cost to maintain the TC Secretariat which were brought to the Executive Council and received support of the Council to issue the counterproposal that ASA would take ISO TC 108 from ASME.

Notably, Batchelder, then Chair of ATAB as well as ASA's Standards Advisor, did not support ASA's position but rather supported transfer of S2 to ASME. In the midst of this uproar, Henning von Gierke became Standards Advisor and Chair of ASACOS in 1973.

At its meeting on 23 April 1974 and subsequently confirmed by letter ballot, ATAB voted 26 to 3 to deny the request of ASME to take over the Administrative Secretariat of S2. The ATAB decision resulted in ASME filing an appeal to the ANSI Executive Standards Council and deciding that if the decision were upheld, they would relinquish TC 108.

On 20 August 1974, the ANSI Executive Standards Council sustained the appeal of ASME against the ATAB decision and ordered the transfer of S2 from ASA to ASME.

ASA appealed the decision of the ANSI Executive Standards Council and at the same time, the ASA Executive Council approved a budget making provision for funding the TC 108 Secretariat. ASA was joined in its appeal by ATAB itself and some individual members of ATAB. On 15 October 1974, the ANSI Executive Standards Council reversed its decision regarding S2 and referred the international question regarding the secretariat of ISO TC 108 back to ATAB.

ASA assumed the secretariat of ISO TC 108 effective 1 January 1975 and has held it along with S2 since that time.

Although the issue of who would administer S2 and TC 108 was settled, it still did not answer the question of which organization was truly the best “home” for standardization in regard to mechanical vibration and shock. From the mid-1950s when S2 was formed, ASA has been concerned with the minimal correlation between the membership of S2 (and the U.S. TAG to ISO TC 108) and ASA. Attendance at S2's meetings held in conjunction with ASA meetings is consistently lower than the other S-Committees. From time to time through the years, S2 meetings have been held in conjunction with other societies and although different people attended those meetings, attendance was not significantly increased. In the 2000s the membership of S2 was polled to try to determine if there was a logical meeting place that would serve them better but nothing was identified.

Free downloads by ASA members of S2's standards are lower than the other S-Committees and even S2's sales are lower. Nevertheless, S2's membership is larger than either S1 or S3, and nearly the same as S12's. And S2's members continue to strongly support having ASA as their secretariat.

In 1994, a consortium of organizations including Self-Help for Hard-of-Hearing People, Inc. (SHHH); Alexander Graham Bell Association for the Deaf and Hard of Hearing (AG Bell); American Speech Language Hearing Association (ASHA); Auditory-Verbal International; National Center for Law and Deafness (NCLD); and the National Cued Speech Association (NCSA), submitted comments to the U.S. Access Board on proposed Rulemaking for State and Local Government Facilities, citing a poor acoustical environment as an architectural barrier to people with hearing and visual impairments. In 1996, the Access Board solicited comments on its plan to amend the ADA Accessibility Guidelines to provide specifications for building elements designed for use by children. These same organizations, along with the Educational Audiology Association (EAA) and the Acoustical Society of America, once again submitted comments identifying poor acoustics as an architectural barrier. In 1997, a parent of a child with hearing impairment wrote a petition for rulemaking to the Access Board. Later that year, S12 established S12/WG 42 to consider standards for classroom acoustics. David Lubman and Louis C. Sutherland were named co-chairs.

To facilitate broad national discussion, the ASA (with funding from the Access Board) hosted a two-day workshop on acoustical barriers to learning in the classroom at the House Ear Institute in Los Angeles in 1997. That initial workshop was attended by 81 professionals and was co-sponsored by several other organizations representing a wide range of stakeholders. A second workshop, “Eliminating Acoustical Barriers to Learning in Classrooms,” was held in February 1999 at the City University of New York. Again, extensive outreach was undertaken in the educational community and by the co-sponsors. Two additional workshops were held in 1999, one hosted by the Fairfax Public Schools in Virginia and the other in Colorado Springs with co-sponsorship by the Colorado Department of Education, among others.

Speakers at these workshops included numerous members of S12/WG 42 as well as experts drawn from the educational facilities sector, educators, and others.

In 1999, the Access Board published a notice in the Federal Register summarizing the responses to its earlier Request for Information and stating its decision to collaborate with ASA in the development of an ANSI Standard on classroom acoustics.

Throughout this time, the working group continued to meet until a draft was circulated for voting in S12 in Jan. 2001. The ballot closed with 2 negative votes, one of which was later reversed. The other negative vote was cast by the Air-Conditioning and Refrigeration Institute (ARI), which is now called Air-Conditioning, Heating and Refrigeration Institute (AHRI). ARI's negative vote was not reversed so a recirculation ballot was conducted in S12 offering the members the opportunity to review the specifics of ARI's objections and reaffirm or revise their vote based on those objections. No members of S12 were convinced to reverse their votes so the document was submitted to ANSI for final approval. ARI appealed this decision under ASA's appeals process. Their appeal was first heard in April 2002 by the ASA Appeals Board which consisted of three members approved by both ARI and ASA: Tony Embleton (chair), Kenneth Eldred, and William Lang. The ASA Appeals Board's decision rejected the appeal but required that one sentence in the text be divided into two for clarity, which the Board identified as editorial. In July, the ANSI Board of Standards Review granted its approval. ANSI S12.60-2002 “American National Standard Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools” was published.

ARI immediately appealed against the decision of the ANSI Board of Standards Review. That appeals hearing was held in Florida with both ASA's President Richard Stern and Schomer speaking on behalf of approving the standard.

A subsequent, and final, appeal was filed by ARI to the ANSI Appeals Board which also upheld the approval of the standard, although ANSI subsequently revised its rules to require an additional committee review of any change made by a Standards Developer's Appeals Board whether it is deemed to be editorial or not.

At the same time, several small organizations also asked ANSI to withdraw the standard “for cause” claiming that it went against the public interest and that they were not notified. These claims were ultimately rejected by ANSI as well. Among these organizations was the Modular Building Institute (MBI) which had concerns about how the requirements of the standard could be applied to modular classrooms, particularly since there can be no assurance that a classroom will be relocated to a site with a similar soundscape.

After the completion of the appeals process, both ARI and ASA were concerned about the residual distrust between the two organizations and took steps to heal the rift. In 2005, ARI took the action to appoint Stephen Lind as its voting representative on S12 and also in S12 working groups. The extreme tact and diplomacy Lind brought to this relationship facilitated the successful reestablishment of communication. Over the following years, Lind became Vice Chair, then Chair of S12 as well as serving as Co-Chair with Schomer of the WG that revised ANSI 12.60: Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools¹¹ in 2010.

Similarly, Schomer reached out to the Modular Building Institute to invite them to engage to find a resolution to their concerns. The Modular Building Institute joined S12 in 2006 and proposed a new project in S12 to consider the application of classroom acoustics standards to relocatable classrooms. A working group was established to address this, co-chaired by Paul Schomer and Tom Hardiman, MBI's Executive Director.

ANSI/ASA S12.60 Part 2: American National Standard Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools, Part 2: Relocatable Classroom Factors¹⁶ was approved by S12 in 2009. Many elements from this standard were later incorporated into the revision of the original standard.

When ANSI S12.60-2002 came up for reaffirmation in 2007, there was some residual opposition and numerous comments to address, including comments received after the close of the comment period in 2002. Work on the new Part 2 document was beginning and it was clear that this work would necessitate revisions to the original standard. In 2009, ANSI S12.60 was finally reaffirmed (and re-designated with the ANSI/ASA acronym) and revision began soon after in an effort to address the remaining open comments and incorporate new material arising from the newly published Part 2.

Since S12/WG 42 had been disbanded, a new working group on classroom acoustics (S12/WG 52) was established consisting of 44 experts and co-chaired by Schomer and Lind. In 2009, with travel support from the Access Board, WG meetings were held in Arlington, VA (30 September–1 October), San Antonio (29 October), and Orlando (15–16 December). A special meeting was held in Syracuse, NY on 17 December to discuss ongoing issues of concern to the AHRI, which was the primary opponent to the first edition of this standard. At the request of the U.S. Access Board, the WG established as its goal the plan to revise the document in time that it might be presented to the International Code Council for inclusion in the next edition of the International Building Code (2012). This also required that the text of the standard be made “code compliant” meaning that all informative elements of the original document had to be stripped out, leaving only the normative elements in the main body of the standard.

Finally the revised, code-compliant draft was approved by S12, becoming ANSI/ASA S12.60 Part 1: American National Standard Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools, Part 1: Permanent Schools in 2010.¹⁷ Both parts are available at no charge to the end user from ASA's online store: https://global.ihs.com/home_page_asa.cfm?&csf=ASA.

ASA also provides three informative booklets on classroom acoustics:

• Classroom Acoustics—A resource for creating learning environments with desirable listening conditions (http://acousticalsociety.org/wp-content/uploads/2018/02/classroom_acoustics_1.pdf),

• Classroom Acoustics II—Acoustical Barriers to Learning (http://acousticalsociety.org/wp-content/uploads/2018/02/classroom_acoustics_11.pdf),

• Classroom Acoustics for Architects—A companion booklet for ANSI-S12.60 (http://acousticalsociety.org/wp-content/uploads/2018/02/Classroom_Acoustics_for_Architects_4_18_15.pdf).

Throughout the years following the publication of these standards, ASA has supported the application of the Access Board, ASHA, and others to have the standards referenced in the International Code Council's Building Codes (ICC). Paul Schomer, Peggy Nelson, and David Lubman each testified on behalf of ASA at ICC hearings. It should also be noted that in addition to those representing ASA, other ASA members participated in the hearings on their own behalf, or that of their own employers, or submitted written comments via the public comment system. Ultimately, ICC A117.1-2017 Accessible and Usable Buildings and Facilities incorporated some elements of ANSI/ASA S12.60-2010.

In 1997, Anne Bowles, then representative of the ASA Technical Committee on Animal Bioacoustics to ASACOS, presented the urgent need of the Animal Bioacoustics community for standardization, particularly in regard to terminology and notation. By 1998, S3 received a proposal from Bowles to develop work related to animal bioacoustics, a subject that was rapidly growing within ASA. The scope proposed and approved by S3 proved to be too expansive to be manageable for standardization and the work foundered for several years. Yet ASACOS continued to hear from the technical community that standards were desperately needed in a number of subjects. Because animal bioacousticians come from diverse sciences (biology, environmental sciences, electrical engineering, ocean sciences, physics, etc.) they do not generally use the same terminology or the same units of measurement. In 2005, the scope of S3/WG 90 was limited to terminology and a new working group, S3/WG 92, Effects of Sound on Fish and Turtles, was formed. In 2007, with support from ASACOS and from the Animal Bioacoustics Technical Committee, S3 voted to form a subcommittee, S3/SC1 on Animal Bioacoustics. David Delaney served as its first Chair.

Despite a good deal of enthusiasm, it has proven difficult for the subcommittee to produce standards. Many of the topics are still active research areas where consensus cannot yet be achieved. Also, the extraordinary number of animal species impacted makes any generalization virtually impossible. Nevertheless, three documents have been published by S3/SC 1:

1. A Technical Report on “Sound Exposure Guidelines for Fishes and Sea Turtles.”¹⁸ 

2. A standard developed jointly with S12, ANSI/ASA S3/SC1.100-2014/S12.100-2014: American National Standard Methods to Define and Measure the Residual Sound in Protected Natural and Quiet Residential Areas.¹⁹ This joint working group between S3/SC 1 and S12 is expected to produce additional standards.

3. ANSI/ASA S3/SC1.6-2018: American National Standard Procedure for Determining Audiograms in Toothed Whales through Evoked Potential Methods.²⁰ 

In the late 1920s, issues related to noise and noise control began to arise in urban centers. In 1929, the New York City Department of Health Noise Abatement Commission performed a noise survey using an audiometer tone adjusted to match the loudness of the noise being measured as judged by the human ear.^21,22

According to Robert W. Young (Fig. 18),²³ “The first quantitative noise measurements appear to have been published by Lemon in 1925, in connection with the then new balloon tires. He adjusted a calibrated buzzer until its sound just masked the sound inside an automobile. Others similarly sought a physical measurement directly related to a sensation such as loudness. The reference sound pressure, in the first American Tentative Standards for Sound Level Meters Z24.3-1936, was chosen as the threshold of hearing for an acute ear. For more than 30 years in Germany, the instrument (whether of the physical or subjective kind) was named a “loudness meter” whose unit of measurement was the phon.

When the Acoustical Society of America joined with the American Standards Association to establish Z24, one of the earliest projects addressed specifications for sound level meters (SLM). Z24.3-1936 was the first sound level meter standard published.

Early sound level meters were large and heavy—some weighing as much as 110 lbs!²¹ There was no standardization in regard to microphones, weighting networks, or indicating instruments. So, it was an achievement when Z24.3-1936 was published. “The standard provided a common reference level and weighting characteristics, desirable meter ballistics and a rule of combination for the rectifier. It indicated the desirability of the non-directional microphone. Last, but not least, the mere existence of the tentative standard gave an impetus to sound level meter development.”²¹ 

Z24.3-1936 set out five “standards” for sound level meters supplemented by several appendixes:

1. A sound level meter shall have a decibel scale. The quantity measured shall be referred to as “sound level.”

2. Frequency weightings A and B were specified, and a “flat” response (which later evolved into the frequency weighting C) was permitted.

3. The reference point of the decibel scale incorporated in sound level meters shall be reference sound intensity (10⁻¹⁶ W per square centimeter) at 1000 cycles in a free progressive wave.

4. Rule of combination—the meter will indicate the sum of the equivalent 1000-cycle free wave intensities of the different single frequency components in the complex wave.

5. Dynamic characteristics of the indicating instrument.

Over time, some other countries published their own sound level meter standards as well. IEC TC 29 was formed in 1953 and began working on an international sound level meter standard. In 1957, the Acoustical Society of America hosted a Symposium on sound level meters at its 53rd meeting to share (and receive) information about the proposed major revision of Z24.3-1944. The Symposium organizers recognized that what was happening internationally in IEC TC 29/WG 8 on Sound Level Meters would also require their attention. Among the papers and reports resulting from that Symposium, Robert W. Young's 1957 report on the “Status of International Standards on Sound Level Meters”²⁴ noted the national differences that were being addressed in regard to weighting curves and units. Young closed by asking readers to provide input on the following:

The major difference between the American National Standard and the standard developed in Europe by the IEC (often referred to as the “Atlantic Divide”) largely related to the sensitivity calibration of the microphone. From 1936 forward, the American standards employed (and by the 1961 edition specifically required) random incidence sensitivity while the IEC standards required sensitivity calibration in a reference direction specified by the manufacturer. In 1979, Young said “By strong tradition in the U.S.A., the goal for the microphone has been frequency-constant sensitivity on the average of all directions; the goal in Germany has been frequency-constant sensitivity perpendicular to the diaphragm.”²⁴ 

This major revision of Z24.3-1944 was complete and published as ANSI S1.4-1961: American National Standard Specification for General-Purpose Sound Level Meters. The IEC published its Recommendation 123 for General-Purpose Sound Level Meters in the same year.

ANSI S1.4-1961 was revised again in 1971 to encompass four types of meters: type 1—Precision; type 2—General Purpose; type 3—Survey; and type S—Special Purpose. The Introduction to this standard points out that sound level meters meeting its requirements for type 1 will essentially satisfy the tolerances of IEC 179:1965 (Precision). The tolerances for type 2 (General Purpose) meters remained the same as the 1961 edition of S1.4 and were generally more stringent than tolerances given in IEC Publication 123:1961 - Recommendations for Sound Level Meters.

Publication of ANSI S1.4-1971 was followed by publication of IEC 651:1979 which was closely aligned with it except that the American National Standard specified random incidence sensitivity where the IEC standards (both IEC 651 and IEC 179) required sensitivity calibration in a reference direction specified by the manufacturer. In a 1983 article in the Noise Control Engineering Journal, Per V. Brüel detailed the relative merits of the two approaches and called for the respective IEC and S1 committees to permit both concepts to be used. The errors for one-inch and half-inch microphones in a direct sound field are described by Brüel,²⁵ and shown in Fig. 19.

However, the draft proposed to S1 in 1982 was a heavily modified version of IEC 651:1979, incorporating hundreds of technical and editorial changes but which perpetuated this important distinction between the two standards. The Foreword to ANSI S1.4-1983 states: “This standard is a revision of the American National Standard Specifications for Sound Level Meters, S1.4-1971. It conforms as closely as possible to the IEC Standards for Sound Level Meters, Publication 651, First Edition, issued in 1979. The principal deviations from publication 651 are: requirement for random-incidence calibration, as had been the United States custom, rather than the free-field method, requirement that the crest factor capability for type 1 instruments be the same, regardless of the inclusion of an impulse exponential-time-averaging characteristic, deletion of the type 3 survey instrument.”²⁶ This draft was approved by S1 in December 1982, but that approval was appealed by R.W. Young who objected on numerous technical and editorial points. His appeal was rejected by ANSI on February 17, 1983 and the standard was published with the 1983 date. It was later modified by Amendment A in 1985 in regard to the tolerances allowed in the A-weighted frequency response at certain frequencies.

Over the years that followed, the IEC issued amendments to IEC 651 (later designated as IEC 60651), and ultimately withdrew that standard upon the publication of IEC 61672 in three parts in 2002. These were later revised in 2013. By this time, many of the U.S. concerns that had thwarted proposals to nationally adopt the IEC standards had been addressed and the “divide” was ultimately resolved in 2014, when S1 approved the identical national adoption of:

Although all three are identical to the IEC standards in their technical content, Part 1 contains an additional informative annex for U.S. users to assist them in applying the new standard when they are required by law or contract to demonstrate adherence to older versions of ANSI S1.4 which may have tighter tolerance requirements at lower frequencies.

By the early 1950s, Z24 had published its first hearing aid standard, Z24.14-1953: “Method for Measurement of Characteristics of Hearing Aids.” This was the first in the line of American National Standards that evolved into ANSI/ASA S3.22.³⁰ The working group (Z24-2-10) that developed Z24.14 was chaired by Samuel F. Lybarger. Over time this became S3/WG 48 which he continued to chair until 1983 when he was succeeded by David A. Preves (Fig. 20), who served as chair until 2017. A conversation with Preves in 2017 is the main source of information for this topic, supplemented by the sources cited in the footnotes.

According to Lybarger et al.,³¹ prior to the publication of Z24.14, efforts to standardize measurements and specification of hearing aids were undertaken by the Council on Physical Medicine of the American Medical Association which set out performance requirements and issued a seal to be affixed to hearing aids deemed acceptable. Participants in these early standardization efforts included Lybarger (Radioear), Vern O. Knudsen (UCLA), J. B. Kelly (Western Electric), S. Sears (Acousticon), and H. Carter (Council on Physical Medicine). Although this group did not actually produce any standards, their work may have influenced the “Tentative Code for Measurement of Performance of Hearing Aids” which was developed by the Technical Committee of the American Hearing Aid Association in 1940, chaired by Frederick W. Kranz. This paper was later published in JASA.³² 

During the earliest years, the American National Standards and the IEC standards developed on their own paths driven by the needs of industry and regulators in the U.S. and elsewhere in the world. As is often the case, many committee decisions are influenced by the personalities involved. Preves recollects that in the earliest years of his involvement in IEC work, members of the U.S. delegation to IEC TC 29 often found that the U.S. proposals were ignored or rejected. Today, however, many of the standards developed by IEC TC 29/WG 13 and S3/WG 48 are closely harmonized.

Preves credits this move toward harmonization to several factors. One important element in this process was the increasing importance of global trade. As the hearing aid industry became more international, the demand for “one standard—one test—accepted everywhere” grew. For example, ANSI/ASA S3.22 includes a requirement in the body of the standard for telecoil tests using the Telephone Magnetic Field Simulator (TMFS) fixture (see Fig. 21).

A test for induction loop sensitivity in a vertical magnetic field is in an informative annex. IEC 60118-7 only required the test for induction loop sensitivity in a vertical magnetic field, as loop systems are more common in Europe than in the U.S. Only recently did the IEC committee agree to include the TMFS telecoil tests as an informative annex.

Preves also credits efforts by the prior and current chairs of IEC TC 29/WG 13 to improve the engagement of the U.S. in IEC TC 29/WG 13. In “Standardizing hearing aid measurement parameters and electroacoustic performance tests.”³³ Preves cites the overture made by Ole Dyrlund, then chair of IEC TC 29/WG 13, who in 1992 attended the meetings of S3/WG 37 (couplers, ear simulators and earphones), S3/WG 48 (hearing aids), and S3/WG 80 (probe tube measurements) and held an ad hoc meeting with interested parties to discuss the path to harmonization. The participants doubted that harmonization would be possible in light of the myriad differences already entrenched in the comparable standards. Technical details are provided in Ref. 33. Nevertheless, all the participants continued to look for areas of possible convergence.

Dyrlund was succeeded as chair of the IEC working group by Gert Ravn. Ravn, as well as some members of IEC TC 29/WG 13, have become active participants in S3/WG 48. Preves notes that Ravn has attended every meeting for more than 10 years. This enables him to obtain a detailed understanding of the issues at play in the U.S. working group. The fact that both the IEC and the S3 working groups are truly international helps define where the standards can be harmonized and where differences are required.

ANSI/ASA S3.22 stands apart from most voluntary consensus standards published by ASA in that adherence to the requirements of this standard are mandated by the U.S. Food and Drug Administration (FDA) which regulates hearing aids. S3/WG 48 works closely with the FDA to ensure that each revision meets the Agency's needs as well as the needs of the other users (e.g., industry, clinicians, and consumers). Normally, there is a lag between the completion of a new edition of ANSI/ASA S3.22 and its adoption by the FDA.

S3/WG 48 has been a prolific producer of standards through the years and is currently responsible for the following standards:

• ANSI/ASA S3.22: Specification of Hearing Aid Characteristics.³⁰ 

• ANSI/ASA S3.35: Method of Measurement of Performance Characteristics of Hearing Aids Under Simulated Real-Ear Working Conditions.³⁴ 

• ANSI/ASA S3.37: Preferred Earhook Nozzle Thread for Postauricular Hearing Aids.³⁵ 

• ANSI/ASA S3.42/Part 1: Testing Hearing Aids with a Broad-Band Noise Signal.³⁶ 

• ANSI/ASA S3.42/Part 2/IEC 60118-15: Testing Hearing Aids—Part 2: Methods for Characterizing Signal Processing in Hearing Aids with a Speech-Like Signal.³⁷ 

The last standard on this list, ANSI/ASA S3.42/Part 2/IEC 60118-15, is the identical national adoption of an IEC standard. According to Ravn and Preves,³⁸ ANSI/ASA S3.42/Part 1 uses a steady-state broadband noise input to determine the hearing aid's frequency response at different input levels. However, using a steady-state broadband noise input does not demonstrate the effects on hearing aid processing using a temporally varying signal such as speech. In this case, the working group S3/WG 48 was struggling to reach consensus on how to extend the testing using a temporally varying signal. At the same time, the International Standards for Measuring Advanced Digital Hearing Aids (ISMADHA) group of the European Hearing Instrument Manufacturers Association (EHIMA) Technical Committee was drafting a hearing aid testing standard using the International Speech Test Signal (ISTS), which was designed to represent normal speech. The ISTS is based on the need for a complex, temporally varying test stimulus with speech properties that facilitates repeatable measurements. The EHIMA ISMADHA document became IEC 60118-15 (2012) and was later adopted, at the recommendation of the S3/WG48 to become ANSI/ASA S3.42/Part 2 (2012).

Harmonization was not always a goal in the world of standardization. Preves³² recounts the history of the Occluded Ear Simulator Standard, ANSI S3.25-1979. This standard, developed by S3/WG 37 with Mahlon D. Burkhard as chair, specified the physical configuration and acoustical performance of the four-branch modified Zwislocki ear simulator, which was then widely used in the U.S. and elsewhere, and a significant improvement over the 2 cm³ coupler proposed by Romanov in the late 1940s. After the publication of ANSI S3.25-1979, the IEC working group, led by Per Brüel, decided to go in another direction. When IEC 711-1981 was completed, S3/WG 37 was shocked to find that IEC 711 specified tolerances that caused the four-branch modified Zwislocki ear simulator to miss the allowable acoustic impedance at a few frequencies by less than 1 dB. However, the specifications did conform to a new ear simulator from Brüel & Kjær that was not yet commercially available at that time. In the 2009 revision of S3.25,³⁹ an effort led by Struck as Chair of S3/WG 37, the legacy Zwislocki and the IEC 60318-4 (formerly IEC 711)⁴⁰ both conform, but have separate tolerances (see Fig. 22). Although the Zwislocki device is no longer commercially produced, many are still widely deployed, particularly for manikin measurements.

ASA has been involved in the development of international standards at least since the end of WW II. ASA has held the US Technical Advisory Group (TAG) for ISO TC 43 since 1947, for IEC TC 29 since 1953, for ISO TC 108 (and its subcommittees) since 1963, for ISO TC 43/SC 1 since 1981, and for ISO TC 43/SC 3 since 2011. Having the U.S. TAG for these ISO and IEC committees is an important role, since the TAG prepares the U.S. position on these committees' standards and nominates U.S. experts to the committee working groups. In the case of each of the committees mentioned above, ASA has provided the TAG from the inception of the TC or SC.

Throughout the years, however, new subjects have arisen and some have been dropped. In the early years IEC TC 29 Electroacoustics, had a broader scope than it has today, including sound recording (now IEC TC 60, Recording), audio engineering (first IEC TC29/SC 60C, later IEC TC 84 and now IEC TC 100, Equipment and systems in the field of audio, video and audiovisual engineering), as well as ultrasound (now IEC TC 87, Ultrasonics). At that time, ASA, by default, provided the TAG on these subjects.

In 1985, when IEC TC 87, Ultrasonics, was created, ASACOS agreed to accept responsibility for the TAG to IEC TC 87 for a one-year trial. By the end of 1988, ASACOS determined that ASA did not have sufficient interest in this subject and did not continue to maintain the TAG for IEC TC 87. By the end of 1989, S3 disbanded S3/WG 54 “Biological and Medical Ultrasound” and all standards work related to medical ultrasound migrated to the American Institute of Ultrasound in Medicine.

During the 1970s and 80s, S2 may have served as “co-TAG” to IEC TC 50A Vibration testing (although it is possible this was an informal arrangement). When that committee was disbanded in 1997 becoming IEC TC 104 Environmental conditions, classification and methods of test, that relationship was lost as IEC TC 104's focus on vibration was limited.

S1 and S3 (and later S12) also served as TAG to ISO TC 94/SC 12 Hearing protection. This committee was disbanded in 1998 by which time it had neither a Secretariat nor a Chair. Hearing protection work was transferred to ISO TC 43/SC 1 Noise, where it remains today.

By the early 1990s, the influence of Europe in international standardization was growing dramatically. As the finalization of the Maastricht Treaty approached and with it the formalization of the European Community, the U.S. Standards community, led by ANSI, put greater focus on the work of the European regional standardization bodies CEN (European Committee for Standardization) and CENELEC (European Committee for Electrotechnical Standardization).

It was easy to understand why the increasingly unified Europe wanted harmonized standards and the value to them of ensuring that the European standards approved by CEN (and CENELEC) would be the same as the relevant International Standard published by ISO (and IEC).

In some committees, the influence of EU Directives is strongly felt. These policies of the EU require international standards to support them. Of particular interest to the committees administered by ASA are the EU Machinery Directive (2006)⁴¹ and the EU Marine Strategy Framework Directive (2008).⁴² 

CEN and CENELEC were able to exert extraordinary influence in their respective ISO and IEC committees, for instance by submitting their Euro-centric standards to be fast-tracked in ISO or IEC, which effectively shut out input from non-European countries. In some cases, ISO or IEC working groups did all their work at CEN or CENELEC meetings without non-European influence.

To address this problem, in 1991, the first Vienna Agreement was signed between ISO and CEN formalizing the relationship. Through the years the Vienna Agreement has been modified to provide better protection for non-European members of ISO. A similar agreement (the Frankfurt Agreement) between IEC and CENELEC was also approved in 1991 and also has been updated over the years.

One of the effects of the growing importance of International Standards was the “metrification” of National Standards. In 1991, ASACOS voted to approve a requirement that all new standards be developed using SI (metric) units only.

In 1991, the impending North American Free Trade Agreement (NAFTA) created a desire among U.S. standards developing organizations to consider closer alliance with Canada and Mexico. For ASA, it was felt that the relationship with Canada was already strong. Canadian members such as George Wong and Tony Embleton were leaders in ASA's Standards Program and ensured the communication between the two. There was little or no interaction with Mexico, so ASACOS established an ad hoc group (Embleton & Muster) to reach out to try to engage them. Although efforts were made over several years, nothing substantial arose from this.

In recent years, the growing influence of China has been a major driver in international standards committees.

Additional details regarding international liaison can be found in Struck.⁴³ 

Details on the formation of ISO TC 108, Mechanical vibration and shock, were presented in Sec. III of this document. When TC 108 was established in 1964, the secretariat was initially provided by ANSI itself, with funding from the U.S. Navy. When the Navy funding stopped in 1970, ASME assumed the secretariat. (See Sec. VI, for more details.) Finally, in 1975 ASA assumed responsibility for the Secretariat and has maintained it ever since.

The chairmanship of ISO TC 108 has been held by the U.S. continuously since its formation, with Horace M. Trent serving from 1964 until his death the next year. At the 1966 meeting, Irwin Vigness assumed the chair, followed by Douglas Muster in 1968. Muster served 20 years, succeeded by Robert Bartheld in 1988. Muster resumed the chairmanship in 1991 until he stepped down to become chair of ISO TC 108/SC 5 in 1993. From 1994 to 1998, during an extremely tumultuous time in the life of the TC, Kenneth Eldred became chair. Eldred was highly esteemed in the fields of acoustics and vibration and for his expertise in national and international standardization. Perhaps most importantly, he was well respected for his tact. A large part of Eldred's effort was focused on resolving the problems arising from the reorganization. Bruce E. Douglas (Fig. 23) was named chair in 1998 and remained chair until 2013 when he was succeeded by David J. Evans, who served one term as chair until 2016. Charles Gaumond became chair in 2017.

From its beginning in 1964 until 1989, ISO TC 108 developed standards in a broad range of topics. By that time, it had four subcommittees:

• SC 1, Balancing.

• SC 2, Measurement and assessment of mechanical vibration and shock as applied to machines, vehicles and structures.

• SC 3, Use and calibration of vibration and shock measuring instruments.

• SC 4, Human exposure to mechanical vibration and shock.

At the same time as ASA was picking up responsibility for the TC Secretariat, the British Standards Institute (BSI) wanted to relinquish responsibility for the Secretariats of SC 1 and SC 3. No countries immediately stepped forward to administer these two SCs so ASA assumed both on a temporary basis in 1975. The SC 3 secretariat was transferred to Danish Standards in 1976.

ASA continued to serve as Secretariat of ISO TC 108/SC 1, Balancing from 1975 until 2002 when ASA sought to relinquish this secretariat. By that time, the work programme of the subcommittee had become very small and there was very little U.S. participation. Since no ISO member body offered to assume this secretariat from ANSI (ASA), the subcommittee was disbanded and became a working group under the Technical Committee and later transferred to ISO TC 108/SC 2's administration.

At its meeting in Milan in March 1990, ISO TC 108 established WG 17, a new working group on “Vibration Condition Monitoring of Rotating and Reciprocating Machines” with Muster as convener. From the start, this was seen to be a “transdisciplinary” subject that would extend beyond the scope of ISO TC 108 which was limited to mechanical vibration and shock. At the Milan meeting the TC rejected the suggestion to seek an expanded scope, deferring discussion of this until the next meeting (Kobe, 1991) and limiting the scope of WG 17 to vibration condition monitoring.

Muster was an energetic and determined proponent of the transdisciplinary nature of the subject of machine condition monitoring. He organized a workshop on Standardization and Condition Monitoring to immediately precede the first meeting of the new WG (March 1991). That workshop identified some 80 potential work items for the new working group.

When Muster resumed the Chairmanship of ISO TC 108 upon the resignation of Robert Bartheld in April 1991, he almost immediately requested that the ISO Technical Management Board (ISO/TMB) expand the scope of ISO TC 108 to encompass condition monitoring and diagnostics as well as to give ISO TC 108 permission to establish a new subcommittee on this subject. By the next month, he presented an extensive plan to reorganize the whole technical committee, proposing four new subcommittees: SC 5 “Condition monitoring and diagnostics of machines”; SC 6 “Vibration and shock generating systems”; SC 7 “Vibration of ships”; and SC 8 “Vibration of land vehicles.” Instead of waiting until the next TC meeting to discuss the details of this proposal as promised, he submitted it for approval by the member bodies with limited consultation. While the elements of this plan were approved, there was strong opposition from several key member countries who felt that Muster had ignored the resolutions of the Milan meeting and proceeded with his plan without first obtaining consensus.

The Kobe meeting in September 1991 was understandably contentious and resulted in agreement on a new scope and new operating procedures that would try to ensure that the subcommittees were engaged in the process of reorganizing the TC and allocation of work items. The new subcommittees previously proposed were put on hold in an effort to resolve the issues. The proposed division would have substantially diminished the scope of SC 2 whose leadership was strongly opposed to the plan. In the end, the proposed SC 7 and SC 8 were never established and that work remains within SC 2 today.

ISO TC 108 leaders met with ISO leaders in Geneva to try to reduce the mistrust and obtain a promise from the Chairman (Muster) that he would respect the TC resolutions. Subsequently, in May 1992 the TMB approved the new scope, and a series of new work item proposals related to condition monitoring were submitted for approval by the national member bodies. The formal proposal to establish a subcommittee on “Condition monitoring and diagnostics of machines” was approved in February 1993, with ANSI as the official Secretariat and management of the Secretariat delegated to ASA. A meeting of the leadership of ISO TC 108 and its SCs was held to allocate the approved condition monitoring work items between the new SC 5 and the pre-existing SCs. While many of the work items were allocated by mutual consent, controversy erupted again in regard to several work items related to data processing, data communication, and data formats. There was general agreement that they should be conducted in a joint working group between SC 2 and SC 5, but there was no agreement as to which SC would be the parent committee. ISO TC 108 met in London in June 1993 and adopted resolutions related to the allocation of the new work items. The resolutions were poorly drafted in that they did not address the parent committee issue clearly. Soon after the meeting, Muster wrote to ISO and to the members to say that he had unilaterally declared the resolutions null and void, which again was met with strong opposition.

In December 1993, Muster resigned as Chair of ISO TC 108 and was succeeded by Ken Eldred, who had just completed a 6-year term as ASA Standards Director. No small part of his mission was to try to regain support and trust of the key members of the TC after the years of divisiveness and contention they had just gone through.

Muster was then named chair of SC 5. The first meeting of SC 5 was held in Swansea, UK in March 1994. In May 1994, a ballot was presented to the member countries of ISO TC 108 proposing allocating the disputed work items to SC 5, essentially ignoring the London resolutions on the basis that the chairman had nullified them.

ISO TC 108 met again in Berlin in September 1994 and the acrimony continued. Eldred did what he could to calm the animosity but the objections continued. In the meantime, SC 5 attempted to diffuse the matter by rewriting the scopes of the disputed work items to remove references to vibration which would put them squarely in the purview of SC 5 and not SC 2, but this was met with distrust.

By July 1995, Canada and the UK had filed formal appeals against the actions of the leadership of both ISO TC 108 and ISO TC 108/SC 5. They were supported by Sweden which filed a complaint although refraining from calling it an appeal. In September the ISO/TMB heard the appeals and reached several conclusions including determining that nullifying the resolutions was not within the authority of the chairman but that the members had properly voted to assign the disputed work to SC 5. In addition, the TMB directed the ISO TC 108 chair to replace Muster as Chair of SC 5. This last resolution was met with objections from Muster himself and from the TC Secretariat (ANSI, via ASA) since his status as Chair had not been part of the complaint and was not known to be on the agenda. Eventually, in 1996, the TMB revised its decision to eliminate the wording that was seen to be a personal attack on Muster and he agreed to resign at the Sydney meeting in September 1996.

Muster was succeeded as Chair of ISO TC 108/SC 5 by Joseph Mathew (Fig. 24) of Australia, who continued as Chair until 2014. Under Mathew's leadership, the SC grew in worldwide participation and produced many standards, carefully following the internal agreement to let SC 2 handle vibration condition monitoring, while SC 5 focused on all other condition monitoring techniques (acoustic emissions, infrared thermography, ultrasound, tribology-based monitoring) as well as prognostics, diagnostics, data processing, communication and formats, and the overview of a condition monitoring program.

When Mathew retired in 2014, the Secretariat nominated Simon Mills (Fig. 25), a U.K. member who had been with the Subcommittee since its inception, to replace him. Mills served one term and was replaced by Leith Hitchcock (Australia) in January 2018.

In 2015, the ASA decided that it no longer wished to support the ISO TC 108/SC 5 Secretariat. SC 5's work programme had little technical relevance to the Society, and, because the subcommittee had become quite large, it required a considerable investment to support. Management of the Secretariat was transitioned to Standards Australia in 2016. ASA still administers the US TAG to ISO TC 108/SC 5.

Although ISO TC 108/SC 6 Vibration and shock generating systems was formed in 1994 as part of the same reorganization that also created SC 5, it did not incite the same upheaval. ISO TC 108/SC 6's secretariat was delegated to the Russian Federation, which still holds it. There was little U.S. interest in SC 6's work and by 2011, no members of the U.S. TAG to ISO TC 108 and its Subcommittees were participating in its working groups or attending its meetings, so ASA disbanded that TAG. Through its role as Secretariat of ISO TC 108, ASA is able to monitor the work of ISO TC 108/SC 6.

In the years that followed the wrenching and contentious reorganization of ISO/TC 108 in the mid-1990s, the amount of work conducted directly under the technical committee (as opposed to its subcommittees) dwindled. During the years between 2000 and the end of his term in 2014, Chairman Bruce Douglas, made many proposals to reorganize ISO/TC 108 and redistribute the work more evenly among its various committees. He hoped to increase efficiency and decrease the number of independent units (subcommittees and working groups). But many of the participants had lived through the earlier reorganization and there was little appetite to reopen this wound. Consequently, it became increasingly difficult for the technical committee to attract sufficient resources to meet independently. Since 2000, at least, it seemed advantageous for ISO/TC 108 to meet in conjunction with ISO/TC 108/SC 3 “Use and calibration of vibration and shock measuring instruments” whenever possible, since there is a good overlap of participating experts.

In 2016, Danish Standards which had long administered the secretariat for ISO TC 108/SC 3 “Use and calibration of vibration and shock measuring instruments” notified the Technical Committee Secretariat that it wished to relinquish the subcommittee. This was discussed at the TC meeting and planning commenced to merge SC 3 into ISO TC 108. When Leif Nielsen, the long-time secretary of ISO TC 108/SC 3, announced his intention to retire at the end of 2017, this presented the opportunity to merge the technical committee and the subcommittee resulting in a more robust and efficient technical committee. The merger was balloted and officially took effect in the first quarter of 2017.

Underwater acoustics has been an important area of research and study in ASA since the earliest time. Looking back, Z24 had a subcommittee on Underwater Sound Measurements in place in 1946. Throughout the years the Navy has been a major proponent and supporter of the ASA Standards program. Underwater sound is specifically identified in the scope of S1 yet, with the exception of ANSI/ASA S1.20: American National Standard Procedures for Calibration of Underwater Electroacoustic Transducers,⁴⁴ no standards specifically addressed the needs of the underwater acoustics technical community.

In 2006, S12 received a proposal to develop a standard for measuring the underwater noise emitted by ships. This subject was becoming increasingly important in the maritime community and among regulators. S12 established a working group and work commenced on a standard. ANSI/ASA S12.64 Part 1: American National Standard Quantities and Procedures for Description and Measurement of Underwater Sound from Ships—Part 1: General Requirements⁴⁵ was published in 2009. This working group attracted participation from several countries including Canada, United Kingdom, Netherlands and Australia, in addition to many U.S. experts. The WG planned to add a Part 2 to this standard dealing with measurements in shallow water, a topic that is mainly of interest outside the U.S.

By 2010, ASACOS perceived that the demand for standards dealing with underwater noise measurement, assessment and reporting was growing, spurred by government regulation requiring environmental impact statements related to increasing undersea construction and exploration, as well as increasing efforts to regulate noise from maritime shipping in environmentally sensitive waters.

It was determined that there were very few standards from any source for underwater noise measurement aside from one ANSI standard and one IEC standard dealing with calibration of hydrophones. To some extent the industry was striving to fill the void with documents such as International Council for the Exploration of the Sea (ICES) Cooperative Research Report No. 209 “Underwater noise of research vessels, review and recommendations”⁴⁶ and Det Norske Veritas (DNV) Rules For Classification of Ships—Part 6, Chapter 24: “Silent Class Notation,” January 2010.⁴⁷ The International Maritime Organization (a specialized agency of the United Nations responsible for regulating shipping) was also working on noise measurement recommendations for the maritime industry.

ASA was not the only organization to recognize this need for formal standardization. ASA learned that ISO TC 8/SC 2, “Ships and marine technology—Marine environment protection” was also planning to begin work on a standard on measuring radiated underwater noise from ships. Unfortunately, they moved ahead with little input from the underwater acoustics community. The chairman of ISO TC 8 stated that it was also their intention to establish criteria levels for injury to marine life, again without input from the technical community.

This made it even more imperative that ASA take the lead in proposing and providing the international secretariat for a new ISO subcommittee on underwater acoustics. The idea of proposing the formation of a new ISO subcommittee was discussed broadly with the ASA Technical Committees at the ASA meeting in Cancun (November 2010) and received strong support.

As a first step the U.S. TAG to ISO TC 43/SC 1 “Noise” (the international counterpart to S12) proposed the international adoption of ANSI/ASA S12.64-2009 Part 1.⁴⁵ The proposal was strongly supported with nine countries naming experts to participate in the newly formed working group. The first working group meeting was held at the next ISO TC 43/SC 1 meeting in London in 2011 and the participants embraced the proposal to form a new subcommittee. The idea was then presented at the plenary meeting of ISO TC 43/SC 1. The delegates there were also enthusiastic about the proposal and it was decided to have the proposal come from the committee rather than be solely a U.S. proposal. Nevertheless, the proposal, including the scope, was prepared by the U.S. participants with considerable assistance from Mardi Hastings, who was then President of ASA.

The ballot on this proposal was met with broad support. Of the 20 countries that voted yes, 11 elected to participate (the minimum participation required is 5.) An additional 5 countries elected to observe. ISO TC 43/SC 3 was officially formed by ISO/TMB resolution 136/2011 on December 2, 2011 with the following scope:

As with all ISO committees, the official national member body, in the case of the U.S., ANSI, is the designated secretariat. However, as it did with ISO TC 108 and ISO TC 108/SC 5, ANSI delegated the administration of the secretariat to ASA. One of the responsibilities of the secretariat is to nominate the chair, and ASA nominated George V. Frisk to serve. Frisk was a former President of ASA and also the 2010 recipient of the Pioneers of Underwater Acoustics Medal. ASA also assumed responsibility for the U.S. TAG for ISO TC 43/SC 3.

The first meeting of the new subcommittee was held at the Woods Hole Oceanographic Institution in June 2012 (where they met again in 2017). ISO TC 43/SC 3 to meet regularly. To date they have published three standards dealing with measuring underwater sound from ships in deep water, measuring radiated underwater sound from percussive pile driving, and terminology.

Once ISO TC 43/SC 3 became active, S12 abandoned its plan to continue work on ship noise in shallow water.

The formation of the new subcommittee did not resolve the competition with ISO TC 8/SC 2, Marine environment protection. ISO TC 8 is seen as one of the most powerful technical committees within ISO, and they had made the claim that anything occurring in the water should be in their scope. With cooperation from ISO staff, ISO TC 8/SC 2 was enabled to bypass required steps in the ISO process and flout the rules to proceed in the development of their standard on measuring underwater noise from ships. Efforts to obtain ANSI's assistance in dealing with this problem were thwarted by the fact that both committees were administered by ANSI Secretariats, making it difficult for ANSI to file any objections to the behavior of the ISO TC 8/SC 2 Secretariat.

The issues were both technical and administrative. When it was discovered that ISO TC 8/SC 2 was working on a standard for measuring noise from merchant ships, ISO TC 43 protested the administrative irregularities to ISO's Technical Management Board. The ISO/TMB decided to allow ISO TC 8/SC 2 to continue to work outside its scope but also forced them to call this a joint working group (JWG) with ISO TC 43/SC 3. Unfortunately, ISO TC 8/SC 2 did not welcome input from underwater acousticians and took many steps to avoid such input such as holding an unannounced meeting in Beijing where the attendees—almost none of whom were formal members of the JWG—rejected all the acoustical comments deeming them “too scientific” to be included in a standard.

This dispute continued. Parts of it were resolved by a meeting between the two Chairmen in 2013 facilitated by the Chair of the U.S. TAG to ISO TC 43/SC 3, Michael Bahtiarian (Fig. 26). The Chairs were able to delineate the types of noise standards that each committee would be best suited to develop going forward.

However, this did not solve the problem regarding measuring noise from ships. ISO TC 43/SC 3 was forced to delay work on its standard, waiting to see what would happen in regard to the ISO TC 8/SC 2 standard. Ultimately, ISO TC 8/SC 2 abandoned its project and ISO/TC 43/SC 3 completed work on ISO 17208-1: Underwater Acoustics—Quantities and Procedures for Description and Measurement of Underwater Sound from Ships—Part 1: Requirements for Precision Measurements in Deep Water Used for Comparison Purposes in 2016.⁴⁸ 

Until 2005, the ANSI standard on loudness was ANSI S3.4-1980, which was based on the work of Stanley Smith Stephens.^49,50 The working group established to revise it, S3/WG 51, was chaired by Rhona Hellman (Northeastern University) and based on the work of Brian Moore and Brian Glasberg (University of Cambridge), who both participated in the WG. The revised standard was published in 2005 and was the first standard published by ASA to be accompanied by software. Soon after its publication, a student working on his Master's thesis discovered a mathematical error in the standard which resulted in a revised version ANSI/ASA S3.4-2007,¹³ published in 2007.

At the time the corresponding international standard was ISO 532:1975,⁵¹ which included two different methods, the Stephens method (ISO 532A) and an early version of the Zwicker method (ISO 532B).

In 2007, based on the recommendation of S3, the U.S. TAG to ISO TC 43, via ANSI, proposed the international adoption of ANSI S3.4-2007: American National Standard Procedure for the Computation of Loudness of Steady Sounds (along with its supporting software) to revise and replace ISO 532-1975. ISO TC 43/WG 9 was established and moved forward initially with the idea to replace the Stephens method (ISO 532A) with the newer Moore-Glasberg method and update the outdated Zwicker method with a method based on DIN 45631-1991,⁵² which was more commonly in use than ISO 532B.

During the ISO TC 43/WG 9 process, procedural objections arose to the idea of encompassing two different methods, which would yield two different results, in the same standard, even though this was already the case in ISO 532. In 2011, the Working Group decided to proceed with adopting a newer version of the Moore-Glasberg method in place of both methods ISO 532A and B.

This action resulted in an uproar from some instrument manufacturers and industrial users of the ISO Standard (including users of the newer DIN method) who were concerned about the continuity of their historical databases, since there are differences in the results between the two methods.

Meetings of the ISO working group became tumultuous, spurring an observer to say that “the loudness working group was the loudest working group!” Laura Ann Wilber (Fig. 27) was appointed convener of the working group, she says, primarily to be an unbiased facilitator and to ensure that all comments are heard. In time, the WG agreed to develop the revision in two parts: ISO 532 Part 1⁵³ based on the revised Zwicker method given in the DIN standard; and ISO 532 Part 2⁵⁴ based on the Moore-Glasberg method. Each part had its own project leader. Technical work on each part has been led by an expert in that particular method. Both parts were published in 2017. Work on a new ISO 532 Part 3 for time varying loudness also commenced in 2017, with several US members, including Wilber, Struck, and Patricia Davies participating in ISO TC 43/WG 9.

Over the years, the urgency to harmonize American National Standards with their ISO and IEC counterparts grew rapidly. Historically, ANSI urged the “adoption or adaptation” of International Standards without limitations. In many cases National and International Standards were developed in tandem–sometimes the documents were the same but often with some differences. This made it preferable to see the standard approved in ISO or IEC first, and then prepare a U.S. “version” incorporating any comments arising from the U.S. Technical Advisory Group review.

Over the years, however, financial and copyright issues mounted. In 1994 ANSI implemented a Sales and Copyright Exploitation Policy to protect its copyright rights to ISO/IEC material. This change created royalties payable to ANSI and, of course, additional expense for ASA. Nevertheless, the ASA S-Committees continued on the path of using national adoption of international standards (NAIS) wherever deemed necessary. In 1994, ASACOS established a Subcommittee on the Production of Acoustical Standards, largely to facilitate the national adoption by S12 of a large number of sound power level standards from ISO TC 43/SC 1/WG 28 (machinery sound emissions) and to examine national adoptions in other committees as well. It was believed that an NAIS offered a new product that would, despite the royalty, be a strong seller and a good source of revenue. Unfortunately, this has not proved to be the case. It turns out that the concept of nationally adopted international standards is not well understood by U.S. users even though it is routine in many countries.

By the late 1990s, S12 began to publish the sound power level standards as national adoptions. In those years, ANSI allowed standard committees to adopt standards developed by ISO or IEC committees under their TAGs, simply by appending the national coversheet identifying it as an “American National Standard” but, over time, the publication requirements established by ISO, IEC and ANSI became more onerous.

Increasingly, questions arose about the degree of correspondence deemed necessary for a committee to choose to nationally adopt an international standard versus developing a unique American National Standard. ANSI became more stringent in regard to the use of text or elements from international standards that were not nationally adopted. Throughout the years, ASACOS addressed this several times generally deciding that minor “national deviations” were permissible in a nationally adopted standard; however, significant changes to mandatory elements of the standard would not be permissible since they could prove confusing.

When it is decided that a candidate ISO or IEC standard has to be modified to obtain approval as an American National Standard, those modifications are called out explicitly in the text, for instance, placed in a text box, labeled as “national deviations,” and/or displayed in a font that is different from the rest of the document. The designation of the document also includes “MOD” to indicate that it contains modifications.

By 2008, this issue came up again in regard to the sound level meter standard. It was proposed that the national adoption could include additional requirements applicable only in the U.S. Thus, any device meeting the U.S. version of the standard would automatically meet the IEC version. Although ASACOS approved this approach, it was not acceptable to the working group or to the voters of S1. Ultimately, the three parts of IEC 61672 were nationally adopted with identical technical content. The U.S. version of IEC 61672-1 contains an additional informative Annex, providing U.S. users with information regarding low-frequency tolerances in the current standard compared to previous ANSI versions.

Despite many concerns about national adoptions, the number proposed and approved has continued to grow. By 2014, national adoptions represented 28% of the ASA Standards catalog. It is easy to understand the benefits of national adoption and in many countries virtually every ISO or IEC standard approved is nationally adopted. By far, the biggest benefit is for industry—manufacturers only have to design and build products to meet one standard rather than having to address different standards in each country where they wish to market their products. For the ASA S-committees there is the benefit that the candidate standard has already been reviewed and accepted by experts worldwide, including members of the U.S. TAGs. U.S. experts work hard on the development of ISO and IEC standards and do not have the time or see any reason for an American version that is nearly identical.

There are also negatives associated with national adoptions. International standards are written to be “globally relevant” and not to meet the specific needs of any particular country or industry. This means that elements that are important only in one country are generally left out at the international level. In some cases, international standards may be (or may be perceived to be) less stringent than existing American National Standards. U.S. users often comment that they miss the “old version” of one or the other standard because it was more rigorous. Furthermore, the ASA S-Committee loses control over the content of the nationally adopted standard. When the ISO or IEC standard is revised, they are required either to adopt the new edition or withdraw the standard entirely. They cannot simply revise the old one since ANSI and ISO or IEC still has a copyright claim to it and doing so would be deemed “use of the ISO/IEC text without national adoption” and subject to financial claims by ANSI. While it is true that the S-Committee can “modify” a nationally adopted international standard to meet national needs, ASACOS has recognized that major modifications are usually not to the benefit of American users. If the U.S. version is more stringent it may harm U.S. manufacturers by making it more expensive to manufacture for the U.S. market. It also could introduce confusion into the market to say that one standard is the national adoption of another and yet it has significantly different requirements. In general, potential users will reject significantly modified national adoptions.

National adoption may also restrict ASA's ability to innovate in areas related to publishing. Recently, under pressure from ISO and IEC, ANSI introduced a change into the contract related to ASA's sale of Nationally Adopted International Standards. Where the old contract allowed ASA to publish and sell the NAIS standard “in any format” the new contract specifically limits ASA to selling nationally adopted standards in print or PDF. This means that ASA would not be able to offer these NAIS in new formats, e.g., in html or formatted for electronic readers.

From time to time, concern has arisen about the status of standards incorporated into the United States Code of Federal Regulations (CFR) by reference. Sometimes, the entire standard would be republished in the U.S. Federal Register or Agencies would use some or all of the text of a standard in a rule. Other agencies that incorporated standards into the law purchased copies and placed them on file for viewing by the public in relevant government offices, thereby making those standards “reasonably available” to the governed public.

By 2010, demand to make standards that are incorporated by reference (IBR) into Federal laws freely available to the public increased. The underlying principle is that the entirety of the law should be available to those who are governed by it.

In 2012, the U.S. Office of the Federal Register, National Archives and Records Administration received a petition from a group of legal scholars requesting that they amend their regulations in regard to what is considered “reasonably available” in the Internet age. The ASA, ANSI, and many other standards developers responded to the call for comments in the Federal Register.

A month later the U.S. Office of Management and Budget (OMB) issued a Federal Register notice to call for comments on the OMB Circular A-119 which outlined the requirements for Federal participation in voluntary standards development and the use of such standards including IBR. Although ASA did not respond to this on its own, ANSI responded on behalf of the entire community with input from ASACOS.

Around the same time, a legal decision in regard to pipeline safety specifically required the U.S. DOT to make all the relevant IBR standards freely available online.

This subject was the main topic of ANSI's annual meeting in October 2012, and it appeared inevitable that if the community of Standards Developing Organizations (SDO) did not take action itself, others—either the courts or activists—would do so. In fact, many of the IBR standards had already been illegally copied and placed on the internet by an organization that is dedicated to putting on the Internet documents it deems should be “free to the public.”

The outcome of the ANSI meeting in 2012 was that ANSI was tasked to develop a portal where standards that are referenced in the CFR can be made available on a read-only basis. It was agreed that the versions placed on this portal would be the version referenced in the CFR, not the current version. (Most, but not all, of the thousands of referenced standards are obsolete.) It was also agreed that only the referenced standard, not the standards referenced within it would be posted. If the standard has been replaced by a newer edition or has been withdrawn, the user will be notified that this is not the latest edition.

The ANSI IBR portal was launched in 2013 (http://ibr.ansi.org/) Relevant ASA-published standards that were referenced in Federal regulations were placed on it the following year.

Initially, both ASA's Headquarters and Standards offices were co-located with AIP in Manhattan. When Schmid was hired as Executive Director in 1990, his office was located in Bainbridge Island, WA, administering both the Headquarters and Standards departments remotely, long before “telecommuting” was common.

When AIP announced its plan in the early 1990s to relocate some of its staff to Woodbury, NY, on Long Island, the Standards Manager, Avril Brenig, expressed a strong preference to remain in Manhattan, at least in part because of the proximity to ANSI's offices. The ASA Headquarters relocated with AIP because there was a need for close linkage between the two staffs because of the number of services AIP provided (and still provides) for ASA.

While seeking a solution that would permit the Standards office to remain in Manhattan, ASA learned of a plan developed by the New York Economic Development Corporation to attempt to keep non-profit organizations from moving out of New York City after a decade-long exodus. A building at 120 Wall Street was to be redeveloped as an “association center” with tax abatements and offering a very reasonable rent. ASA's space needs for its Standards Program were relatively small so it was possible to obtain space in this building as a sub-tenant of the American Vacuum Society (AVS), another of the member societies of AIP. The Standards office remained in this location from 1993 until 2001.

When Brenig retired at the end of 2000, the ASA Executive Council decided to reunify the two departments, Standards and Headquarters, in the AIP building which was by then located in Melville, NY. A new Standards Manager, Susan Blaeser, was hired and given the mandate to move the office as soon as possible. However, it was soon determined that the space available in the AIP office was insufficient. Blaeser was instructed to find alternate space close to the ASA Headquarters, which was accomplished by mid-2001. The Standards office occupied that space until 2014 when AIP once again relocated, still in Melville, NY, and both ASA Headquarters and ASA Standards staff were accommodated together in a sub-tenancy.

This unification of the Standards Office with the Headquarters Office coincided with the beginning of Susan Fox's tenure as Executive Director. Fox assumed this role upon Schmid's retirement at the end of 2013.

The ASA Standards Program is a financial cost center within the Society, providing a strategic service and benefit to ASA members and the acoustics community at large. Since its inception, it has been a pillar of the society. Fortunately, with several revenue sources, the program is able to recover the majority of its costs. Organizational member fees paid by members of the S-Committees and the U.S. TAGs provide just over 50% of revenues. Sales of standards currently cover approximately 25% of the cost of the standards program. Therefore, the cost to the Society to support the ASA Standards Program is on average only 25% of its actual expenses.

Beginning in 1968 when ASA hired Avril Brenig as a part-time secretary to support the three ASA S-Committees, ASA's investment in the development of standards began to expand as did the productivity and scope of the program.

The addition of staff, postage, and travel costs related to assuming the international secretariat of ISO/TC 108 in 1975 and later, additional costs related to publication and sales of ASA's American National Standards, resulted in a dramatic increase of expenses. Revenue from sales offset some of the expenses. ASACOS's time was increasingly focused on the budget.

Over the years, ASA was able to obtain financial support for the Standards Program in the form of gifts from interested parties and occasional grants and contracts from government agencies. Although some of these contracts were sustained over many years, it was, and is, impossible to rely on such support for operations.

In 1982, ASA implemented a fee of $300 for organizational membership in one of the S-Committees. This resulted in a few members dropping out but most of them stayed recognizing the value of their participation in standards development. Fees were raised sporadically over the years usually in response to a financial threat ($400 in 1987; $600 in 1994; $750 in 1997, $1000 in 1999).

By 1990, the ASA Executive Council became increasingly concerned about the increasing budget deficits faced by the standards program and implemented a cap to reduce ASA's contribution from 45% of the Standards budget in 1990–91 to 30% by 1994–95.

Financial stress continued to increase as ANSI fees increased rapidly and other costs (rent, travel, salaries, benefits, office technology, etc.) increased as well. In 1999, as part of a “Five-year Plan for the Standards Program to become Profitable” the ASA Executive Council replaced the 30% cap on ASA's support of the Standards Program with a decreasing schedule of support: $95 000 for 1999 diminishing to $50 000 in 2002.

Although the Standards Manager (Brenig) was extremely adept at obtaining contracts and gifts, this income was unreliable and insufficient to balance the budget. Many efforts were made to reassess and improve the standards business model, enhance marketing, etc. Free standards (chosen from overstocked copies of printed standards) were distributed at meetings to introduce the product to ASA's members. “Bundles” of related standards were offered as special deals. An arrangement to offer full sets of ASA standards to educational institutions, steeply discounted, was brought forward.

When Brenig retired at the end of 2000, it was clear that the ASA cap on funding standards activities could not be met and furthermore it was unlikely that the (even lower) 2001 cap could be met. Additionally, ASA would face unusual costs related to Brenig's retirement, training the new ISO TC 108 Secretary in advance of the upcoming TC 108 (and subcommittees) meeting, and relocating the Standards Office. At its meeting in December 2000, ASACOS discussed the urgent need for fundraising and established an ad hoc group consisting of Bennett Brooks, Bruce Douglas, Paul Schomer, George Wong, and Susan Blaeser (the newly hired Standards Manager) to work on this.

In response to the change of Standards Manager, ANSI asked ASA if it remained committed to its contractual obligations in regard to providing the secretariats for ISO/TC 108, ISO/TC 108/SC 1, and ISO/TC 108/SC 5. A special meeting of the ASA Officers and Managers Group was called for January 2001 to consider the future of ASA's support for TC 108.

Based on strong support from ASA's Technical Committees, ASA agreed to continue to support the three secretariats if funding could be found by 2002. Organizational member fees were increased to $1500 in 2002 and a tiered fee structure was implemented to ensure that smaller organizations would not be driven away. New organizational members were aggressively recruited along with government contracts and grant support. Gradually the percentage of financial support for the standards program coming from member fees increased from about 15% to more than 50%. Throughout his tenure as Standards Director, Schomer generally recommended small increases in fees each year to keep up with increases in expenses. This trend continues to the present day.

The organizational members of the S-Committees administered by ASA have been consistent supporters over the years. With the exception of a dip in member participation which was linked to the major disruption in the national economy around 2009, the S-Committees have enjoyed a high level of year-to-year member retention (usually near 95%). Many member organizations have participated for 25 years or more.

As Standards Director, Schomer sought new sources of funding for the standards program and new ways to introduce standards to potential users. One example is the Classroom Acoustics Partners Program, whereby industry partners provide an annual payment sufficient to allow ASA to make the classroom acoustics standards (ANSI/ASA S12.60-Parts 1 and 2) available to the public at no cost to the end user. This program has been in place since 2005.

Prior to 2007, revenue from standards sales and memberships was approximately equal. The percentage of revenue from standards sales has diminished over the years, in part because, since 2007, ASA has made 5 national standards per year available at no cost to all ASA members (including student members) as a member benefit. Nationally Adopted International Standards (NAIS) are also made available at a steep discount.

In the early 1970s, spurred by ASME's contention that revenue from sales of standards could offset the cost of sponsoring standards committees, ASA began to explore the possibility of publishing its own standards. An ad hoc committee on publishing was convened and in November 1972 it recommended that ASA should continue to publish through ANSI but also continue to explore the costs and potential benefits of self-publishing. By November 1974, the ad hoc committee recommended that ASA begin a publishing program citing five reasons in support of this: (1) revenue to be obtained and channeled back into support of the ASA Standards Secretariat; (2) cutting down the length of time required for standards processing from inception to publication; (3) stronger position and greater status as a society via publication plus more recognition for time, effort, and money expended in standards developed; (4) ability to publish standards which ANSI does not approve or approves with long delay; (5) possibility of obtaining outside funding to support the publication effort.

Beginning in 1975, ASA entered into an agreement with the American Institute of Physics (AIP) to provide copyediting and publication services such as are provided for other ASA publications. At that time, all standards were published in paper format only and close budgeting of annual page counts was critical. ASACOS formed a Subcommittee on Publishing which guided the establishment of this part of the standards program. The agreement with AIP continued until the early 2000s when the publication of ASA-copyrighted standards began to be handled by staff in the ASA Standards office.

By the late 1970s, ASA had published about a dozen standards under its own publication program. As older, ANSI-copyrighted standards were revised the copyright reverted to ASA. Today, ASA is responsible for about 120 American National Standards including nationally adopted international standards. (See Sec. XVIII.)

Now that sales revenue was beginning to be a factor in supporting the program, questions about copyright began to be more important. Concern was expressed about instances where a standard is published in its entirety in the Federal Register as part of the rulemaking process. This issue reasserted itself in 2012 when there began to be increasing pressure to make standards that are “incorporated by reference” into the Code of Federal Regulations freely available online. (See Sec. XIX.)

There were also instances where individual participants challenged the ASA's ownership of the copyright to standards. In the early 1990s, a copyright dispute between R. W. Young and ASA resulted in a delay of more than a year in the publication of S1.22–1992.

In general, at this point, it is deemed that individuals participating in the development of a standard should only contribute material they are willing to see published under the ASA copyright; however, ASA's right to publish does not impede the author from reusing his original contributions elsewhere in his or her own publications. ASA is happy to grant permission to quote or copy tables and figures from currently valid standards in other works, upon request. A request form appears on the website.

The publication and distribution of standards began to change around 1990 and ASA made a strong effort to keep up with the changes. Although ASA's own publication program was still limited to paper copies, ASA contracted with resellers that offered new formats such as microfiche and PDF. Standards were (and still are) also offered by subscription and as part of industry-specific bundles by some resellers. ASA executed several reseller agreements so that it could meet the needs of all its customers.

By the late-1990s draft documents began to be submitted to ASA on diskette for ballot and later for publication. While this streamlined the process for some, it caused a lot of extra work for others. Many WG Chairs, in particular, were overwhelmed by the transition to PC word processing and looked for financial support to have someone “put documents onto diskettes” for them. Complicating matters further, once AIP received a document in Microsoft Word (or other common word processing formats) and transferred it into its publication system, there was no way to get a revisable copy back. This meant that when it was time to revise a document, the WG Chair had only the submitted copy, not the as-published version! This problem was resolved when ASA began publishing in-house. Currently an ASA Standards staff person works with the WG Chair to edit the draft before ballot and again after the final resolution of comments. When the document is published, the Chair receives a revisable copy of the as-published document for use in future revisions.

ASA was, and still is, an innovator in developing standards that are accompanied by software that will assist the user to implement the standard. In 2014, led by Struck, ASACOS approved a formal document setting out Guidelines for Software Developed to Accompany ANSI/ASA Standards.

With the help of George Maling and other volunteers, in the late 1990s an ASA Standards “home page” was set up to display a list of ASA's Published standards. Later, AIP was engaged to develop and support an online store for ASA which opened in early 2001. AIP continued to provide this service until the store migrated to management by IHS in 2015.

In 1998, ASA engaged in a contract with ANSI allowing ASA to sell the ISO and IEC standards for those committees for which it served as U.S. TAG. ANSI imposed stiff royalties making this a member service more than a revenue generator for ASA. Few members purchased ISO and IEC standards from ASA and eventually this was discontinued when IHS assumed management of the ASA Standards store.

ASA began working on standards in 1929 and began working with the predecessor to ANSI by 1932. The Executive Council of ASA receives a report on ASA's Standards activities at every meeting. Since 1968, ASA has employed staff—currently 2.7 full time employees—to perform the support work necessary to facilitate the development of both American National Standards and International Standards within ISO and IEC.

Since its inception, ASA's leaders, including numerous presidents, have been actively involved in the Standards Program as subject-matter experts in working groups, working group chairs, standards committee leaders and in ASACOS. The persons mentioned in this paper represent the “Who's Who” of ASA.

There are no records from the years that the first ASA-sponsored standards committee, Z24, operated, but from the Executive Council minutes we do know that Vern O. Knudsen served as its chair for about 20 years from its inception. In addition, he was a leader in every aspect of ASA and was recognized by ASA three times: He was named an Honorary Fellow in 1954; received the Wallace Clement Sabine Medal in 1957; and the Gold Medal in 1967.

Many of ASA's leaders followed Knudsen as chair of Z24 and the S-Committees that came later. Table I lists only those who served ASA in the role that is now titled Standards Director.

In 2009, the following comments were presented to the Executive Council and to ASACOS to shed some light on the involvement of ASA members in ASA's standards program (ASACOS/364):

While the exact numbers have changed from time to time, it is believed that the essence of this statement still holds true. ASA Members and Fellows are active participants at every level in the work of the standards committees and this work continues to provide an essential opportunity for ASA to fulfill its purpose “to generate, disseminate, and promote the knowledge and practical applications of acoustics.”

This history is primarily compiled from the Minutes of the ASA Executive Council meetings and, after 1970, from Minutes of the meetings of the ASA Committee on Standards, other source documents available in the ASA Standards office, and articles and reports appearing in the Journal of the Acoustical Society of America. In addition, telephone interviews were conducted with selected experts who helped provide context and background. Many thanks are due to the following persons for their assistance and for sharing their time and their memories.

• Les Blomberg

• Tony Embleton

• Ronald Eshleman

• Robert Hellweg

• Caryn Mennigke

• Elaine Moran

• William Murphy

• David Preves

• Paul Schomer

• Charles E. Schmid

• Kat Setzer

• Laura Ann Wilber

In regard to the chapter on Hearing Aid Standards, David Preves was kind enough to provide several journal articles and book chapters detailing the journey toward harmonization between ASA Standards Committee S3 and IEC TC 29.

Paul Schomer and Les Blomberg provided many resource documents on the history of the sound level meter.

ACGIH

American Conference of Governmental Industrial Hygienists

ADA

Americans with Disabilities Act

AHAM

Association of Home Appliance Manufacturers

AHRI

Air-Conditioning, Heating and Refrigeration Institute

AIP

American Institute of Physics

ANSI

American National Standards Institute

ARI

Air-Conditioning and Refrigeration Institute (now AHRI)

ASA

Acoustical Society of America

ASACOS

Acoustical Society of America Committee on Standards

ASB

American Standards Association Acoustical Standards Board

ASHA

American Speech Language Hearing Association

ASMB

Acoustical Standards Management Board

ASME

American Society of Mechanical Engineers

ATAB

(ANSI) Acoustical Technical Advisory Board

AVS

American Vacuum Society

AVSB

Acoustical and Vibration Standards Board

BSI

British Standards Institute

BSR

Board of Standards Review

CEN

European Committee for Standardization

CENELEC

European Committee for Electrotechnical Standardization

CFR

(U.S.) Code of Federal Regulations

DIN

Deutsches Institut füür Normung (German Standards Institute)

EC

(ASA) Executive Council

EHIMA

European Hearing Instrument Manufacturers Association

EU

European Union

EPA

(U.S.) Environmental Protection Agency

FDA

(U.S.) Food and Drug Administration

IBR

Incorporated by reference

ICC

International Code Council

ICES

International Council for the Exploration of the Sea

IEC

International Electrotechnical Committee

IEEE

Institute of Electrical and Electronics Engineers

IEST

Institute of Environmental Sciences and Technology

IMO

International Maritime Organization

JWG

Joint Working Group

ISMADHA

International Standards for Measuring Advanced Digital Hearing Aids

ISO

International Organization for Standardization

MBI

Modular Building Institute

NAIS

Nationally Adopted International Standard

NBS

National Bureau of Standards (now NIST)

NCLD

National Center for Law and Deafness

NCSA

National Cued Speech Association

NIST

National Institute of Science and Technology (U.S.)

OMB

(U.S.) Office of Management and Budget

SAE

Society of Automotive Engineers

SC

Sub-Committee

SDO

Standards Development Organization

SHHH

Self-Help for Hard-of-Hearing People

TAG

Technical Advisory Group

TC

Technical Committee

TLV

Threshold Limit Value

TMB

Technical Management Board

USASI

United States of America Standards Institute (now ANSI)

USNC

United States National Committee

WG

Working Group