The purpose of these acoustical patent reviews is to provide enough information for a Journal reader to decide whether to seek more information from the patent itself. Any opinions expressed here are those of the reviewers as individuals and are not legal opinions. Patents are available via the internet at the USPTO website.

  • GEORGE L. AUGSPURGER, Perception, Incorporated, Box 39536, Los Angeles, California 90039

  • JAMES DEGRANDIS, Acoustics First Corp., 2247 Tomlin Street, Richmond, Virginia 23230

  • ERIC E. UNGAR, Acentech, Incorporated, 33 Moulton Street, Cambridge, Massachusetts 02138

Min Zhang et al., assignors to BYD COMPANY LIMITED

16 March 2021; filed 21 December 2016

To a substrate of ethylene propylene diene rubber, which has good damping characteristics, there are added flake-shaped mica powders and block-shaped dolomite. These increase the local strains, thus increasing the energy absorption. They also make the system porous, increasing the sound absorption.—EEU


16 March 2021; filed 3 June 2019

Numerous existing patents describe schemes for downmixing multi-channel audio into a smaller number of channels. In the method described here, channels are grouped according to loudspeaker positions, and weights are then assigned to individual channels. During the downmixing process, side speakers are given a lower priority than front speakers.—GLA

Ryan C. Struzik et al., assignors to Bose Corporation

16 March 2021; filed 11 September 2019

This earbud sits adjacent to the wearer's ear, but is not inserted. Front and rear radiation are both vented, but the front radiation vent lies closer to the ear. The 18 patent Claims are mostly a list of nitpicky definitions and restrictions.—GLA

Bret Hauser and Thaddeus S. Milburn, assignors to Medtronic X omed, Inc.

23 March 2021; filed 14 February 2019

This patent describes a hand-held tool that may be used for certain surgical procedures. The tool contains a motor and a tubular arrangement on whose tip is located a cutting element or the like. Vibration isolation at selected frequencies is provided by selecting the thickness and length of the tubular support arrangement.—EEU

Brandon E. Ricketts et al., assignors to Honda Motor Co., Ltd.

23 March 2021; filed 13 May 2019

An all-terrain vehicle (ATV) is usually fitted with dual-spring shock absorbers. An extra-stiff upper spring 134 comes into play when the lower spring 136 has been mostly compressed. If part of the assembly becomes worn or damaged, the entire shock absorber must be discarded. The design disclosed in this patent can be easily disassembled, and only the worn parts replaced.—GLA

Ilkka Rissanen et al., assignors to Genelec Oy

23 March 2021; filed 3 July 2019

The front panel of a small, vented loudspeaker system may not have enough room for the vent opening, and it is fairly common to put the vent on the back panel instead. In a few designs the vent is on a side panel. This patent adds to the sum of human knowledge by moving the vent to the bottom. If the loudspeaker is mounted on a wall, the vent functions normally. But if the speaker is intended to sit on a shelf or a table then a special stand 120 must be fastened in place. “The clearance provided by the stand elevates the reflex port opening from the surface supporting the loudspeaker thus enabling free air flow in the reflex port.” It also creates a long waveguide that lowers the vent resonance frequency a half-octave or so, which apparently did not occur to the inventors.—GLA

Masaki Katayama et al., assignors to Yamaha Corporation

23 March 2021; filed 12 April 2018

This Yamaha patent is concerned with a home entertainment system in which multi-channel audio is heard from a soundbar augmented by rear speakers 2a,2b. During setup, the system calculates the location of each rear speaker (lateral displacement and distance) by emitting test signals from speakers 21a,21b in the soundbar and then picking up the signals from a microphone 22 in each rear speaker. In another embodiment, test signals are emitted from the rear speakers and picked up by a microphone array in the sound bar.—GLA

Daniel A. Del Vecchio

30 March 2021; filed 12 June 2018

A cannula is an instrument that is used in cosmetic surgery to deliver or remove fluid or fat from a body. This patent describes a motorized cannula, the actuator of which is configured to vibrate in a range of frequencies. A readout system provides information on the vibrations and other data.—EEU

Philip Olsson and Hans-Erik Eldemark, assignors to COLLABSTOR AB

30 March 2021; filed 10 November 2016

The vocal booth as shown in the figure is configured to be portable and to accommodate singers' heads of various sizes. The walls and the rear of the booth are lined with sound-absorbing materials that can be changed for voices of different strengths.—EEU

Daniel J. Mennitt et al., assignors to Colorado State University Research Foundation

30 March 2021; filed 22 April 2019

Pressure microphones used for acoustic measurements must be periodically calibrated. Calibration is usually done by coupling the microphone to a small closed cavity that is driven by a diaphragm or piston. Suitable adaptor gaskets are provided for specific microphones and for microphones of standard diameters. This patent describes a coupler that can be used to calibrate odd-size and odd-shaped microphones. A resilient, permeable gasket 108 (called a “flexible membrane”) provides a tight fit to the housing of microphone 120. “In contrast to a rigid enclosure, the permeability of the membrane creates an open system that reduces the sensitivity to fit.” The patent includes test results that demonstrate the accuracy of the device.—GLA

William Rodriguez et al., assignors to Universal Studios LLC

6 April 2021; filed 11 June 2019

The seats, restraining bars, and/or hand rails of a one-person ride are provided with rotating eccentric masses that are driven by controlled-speed motors. Some of the installations may include sensors and controllers configured to provide the desired vibration intensity at selected ride locations.—EEU

Xinping Lin et al., assignors to BYD COMPANY LIMITED

6 April 2021; filed 21 December 2016

This patent is very similar to U.S. Patent #10,947,374, except that it uses a different substrate material and different portions of the additives.—EEU

Robert Blake Schmutz and Daryl C. Wilson, assignors to Wilson Audio Specialties, Inc.

6 April 2021; filed 7 October 2020

Loudspeakers and other audio equipment may be mounted on resilient blocks or pads to minimize vibration transmission. The design shown here is a button-type pad in which the resilient material is enclosed by a rigid telescoping case. The upper section of the case is shaped to accommodate a mounting foot of the equipment above.—GLA

Randy Ray Johnson et al., assignors to General Electric Company

6 April 2021; filed 20 March 2018

An enclosure for a marine gas turbine engine is made of a monolithic composite material rather than steel plates. An internal “acoustic barrier” and a “sound absorption member” further reduce noise transmission. A comparison of exterior sound levels shows that the composite enclosure achieves more noise reduction above 250 Hz, but is about 5 dB less effective at lower frequencies (probably because of the lighter-weight construction).—GLA

Shogo Yamazoe et al., assignors to FUJIFILM Corporation

6 April 2021; filed 20 December 2017

Attenuating noise while maintaining air permeability is a difficult endeavor. When having ductwork, louvered air passages, or other ventilation openings where air is permitted passage, sound and noise generally travel with it. Changing the free path of air travel, implementing absorption, and creating other obstacles to sound transmission are methods generally implemented to reduce sound intensity, but come at a cost to air permeation. This patent introduces a method of tuning the attenuation of targeted frequencies using cells of different sizes and orientations within the ductwork, or louvered passage. The cells do have an impact on air permeability, but systems can be designed in a way to reduce that impact to a far lesser impedance than previous methods, many of which require an increased airflow rate or volume to maintain desired ventilation. By creating resonant absorber cells at different incident angles, the impact on noise is greater than the impedance to airflow. In one embodiment, lining the louvers of a ventilation portal with cells optimized to attenuate noise arriving from routable and predictable angles of incidence is proposed. By designing the louvers to direct noise across the cells at specific incident angles, there is high impact on noise reduction, with a minimal impact on air permeability; a novel approach if you know the general direction of the source of the noise you are wishing to attenuate, as in a high-rise structure.—JD

J. Douglas Rollow IV et al., assignors to Sennheiser electronic GmbH & Co. KG

6 April 2021; filed 15 August 2019

This patent is a companion to U.S. Patent # 9,894,434 B2. Both patents describe an audio conference setup in which the voices of individual participants are picked up by a steerable array of ceiling microphones. The second patent describes a more elaborate method for steering multiple pickup beams. The method involves a search grid of predetermined spatial positions, including direction and distance.—GLA

Kai-Ping Chang et al., assignors to HONG FU JIN PRECISION INDUSTRY (ShenZhen) CO., LTD.

6 April 2021; filed 28 May 2019

Loudspeaker production usually involves shims and glue. This design uses a pre-assembled cone and basket instead. It simply drops into place during final assembly—much the same as a high frequency horn driver.—GLA