Artificial sound masking is increasingly used in open-plan offices to improve speech privacy and to reduce distraction caused by speech sounds. Most of the masking sounds are based on pseudorandom continuous noise filtered to a specific spectrum that should be optimized in respect with speech masking efficiency and comfort. The aim of this study was to increase basic understanding regarding the comfort. The second aim was to determine how well objective rating methods (15 different noise indices) predict the subjective ratings. Twenty-three subjects rated the loudness, disturbance, pleasantness, and six other subjective measures of 11 spectrally different noises in laboratory conditions. Speech was not present during the experiment. All sounds were presented at 42 dB LAeq within 50–10 000 Hz. Unexpectedly, the subjects were most satisfied with sounds having emphasis on low frequencies. A sound having a slope of −7 dB per octave increment resulted in the highest satisfaction. Changes in subjective ratings were reasonably well predicted by five noise indices, while many well-known noise indices frequently used in building design underperformed in this task. The results are expected to benefit in the design of masking sounds and other appliances.
References
1.
ANSI
(2007
). S3.4, Procedure for the Computation of Loudness Steady Sounds
(Acoustical Society of America
, New York)
.2.
ANSI
(2008
). S12.2, Criteria for Evaluating Room Noise
(Acoustical Society of America
, New York)
.3.
Ayr
, U.
, Cirillo
, E.
, Fato
, I.
, and Martellotta
, F.
(2003
). “A new approach to assessing the performance of noise indices in buildings
,” Appl. Acoust.
64
, 129
–145
.4.
Bengtsson
, J.
, Persson Waye
, K.
, and Kjellberg
, A.
(2004
). “Evaluations of effects due to low-frequency noise in a low demanding work situation
,” J. Sound Vib.
278
, 83
–99
.5.
Beranek
, L. L.
(1956
). “Criteria for office quieting based on questionnaire rating studies
,” J. Acoust. Soc. Am.
28
(5
), 833
–852
.6.
Beranek
, L. L.
(1971
). Noise and Vibration Control
(McGraw-Hill
, New York)
, p. 592
, Fig. 18.15.7.
Beranek
, L. L.
(1989
). “Balanced noise criterion (NCB) curves
,” J. Acoust. Soc. Am.
86
(2
), 650
–664
.8.
Beranek
, L. L.
, and Blazier
, W. E.
(1971
). “Preferred noise criterion (PNC) curves and their application to rooms
,” J. Acoust. Soc. Am.
50
(5
), 1223
–1228
.9.
Blazier
, W. E.
(1997
). “RC Mark II: A refined procedure for rating the noise of heating, ventilating, and air-conditioning (HVAC) systems in buildings
,” Noise Control Eng. J.
45
(6
), 243
–250
.10.
Bradley
, J. S.
(2003
). “The acoustical design of conventional open plan offices
,” Can. Acoust.
31
, 23
–31
.11.
BS 8233
:1999 (1999
). Sound Insulation and Noise Reduction for Buildings
(British Standards Institution
, London
).12.
Danielsson
, C. B.
, and Bodin
, L.
(2009
). “Difference in satisfaction with office environment among employees in different office types
,” J. Arch. Plan. Res.
26
(3
), 241
–257
.13.
Glasberg
, B. R.
, and Moore
, B. C. J.
(2006
). “Prediction of absolute thresholds and equal-loudness contours using a modified loudness model
,” J. Acoust. Soc. Am.
120
, 585
–588
.14.
Haapakangas
, A.
, Helenius
, R.
, Keskinen
, E.
, and Hongisto
, V.
(2008
). “Perceived acoustic environment, work performance and well-being—survey results from Finnish offices
,” in Ninth International Congress on Noise as a Public Health Problem (ICBEN)
, July 21–25, Mashantucket, CT
.15.
Haapakangas
, A.
, Kankkunen
, E.
, Hongisto
, V.
, Virjonen
, P.
, Oliva
, D.
, and Keskinen
, E.
(2011
). “Effects of five speech masking sounds on performance and acoustic satisfaction—implications for open-plan offices
,” Acta Acust. united Ac.
97
(4
), 641
–655
.16.
Haka
, M.
, Haapakangas
, A.
, Keränen
, J.
, Hakala
, J.
, Keskinen
, E.
, and Hongisto
, V.
(2009
). “Performance effects and subjective disturbance of speech in acoustically different office types—a laboratory experiment
,” Indoor Air
19
(6
), 454
–467
.17.
18.
Helenius
, R.
, and Hongisto
, V.
(2004
). “The effect of acoustical improvement of an open-plan office on workers
,” in Proceedings of Inter-Noise 2004
, August 21–25, Prague, Czech Republik
, Paper 674.19.
Hongisto
, V.
(2005
). “A model predicting the effect of speech of varying intelligibility on work performance
,” Indoor Air
15
, 458
–468
.20.
Hongisto
, V.
(2008
). “Effect of sound masking on workers—a longitudinal study in an open office
,” in Acoustics'08
, June 29–July 4, Paris
, Paper 1178.21.
Hongisto
, V.
, Haapakangas
, A.
, Helenius
, R.
, Keränen
, J.
, and Oliva
, D.
(2012
). “Acoustic satisfaction in an open-plan office before and after the renovation
,” in Euronoise 2012
, June 10–13, Prague
, pp. 654
–659
.22.
Hongisto
, V.
, Oliva
, D.
, and Keränen
, J.
(2014
). “Subjective and objective rating of airborne sound insulation—living sounds
,” Acta Acust. united Ac.
100
, 848
–863
.23.
IEC 60268-16
:2003 (2003
). Sound System Equipment. Part 16: Objective Rating of Speech Intelligibility by Speech Transmission Index
(International Electrotechnical Commission, Geneva, Switzerland).24.
ISO 532
:1975 (1975
). Acoustics—Method for Calculating Loudness Level
(International Organization for Standardization
, Geneva, Switzerland
).25.
ISO 226
:2003 (2003
). Acoustics—Normal Equal-Loudness-Level Contours
(International Organization for Standardization
, Geneva, Switzerland
).26.
ISO 3382-3
:2012 (2012
). Acoustics—Measurement of Room Acoustic Parameters. Part 3: Open Plan Offices
(International Organization for Standardization, Geneva
, Switzerland
).27.
ITU-R BS 1116-1
:1994–1997 (1994
). Recommendation, Methods for the Subjective Assessment of Small Impairments in Audio Systems Including Multichannel Sound Systems
(International Telecommunication Union
, Geneva, Switzerland
).28.
Jensen
, K. L.
, Arens
, E.
, and Zagreus
, L.
(2005
). “Acoustical quality in office workstations as assessed by occupant surveys
,” in Proceedings of Indoor Air, Tenth International Conference on Indoor Air Quality and Climate
, September 4–9, Beijing, China
, pp. 2401
–2405
.29.
Jones
, D. M.
, Miles
, C.
, and Page
, J.
(1990
). “Disruption of proofreading by irrelevant speech: Effects of attention, arousal or memory?
,” Appl. Cogn. Psychol.
4
(2
), 89
–108
.30.
Kaarlela-Tuomaala
, A.
, Helenius
, R.
, Keskinen
, E.
, and Hongisto
, V.
(2009
). “Effects of acoustic environment on work in private office rooms and open-plan offices—longitudinal study during relocation
,” Ergonomics
52
(11
), 1423
–1444
.31.
Keighley
, E. C.
(1970
). “Acceptability criteria for noise in large offices
,” J. Sound Vib.
11
(1
), 83
–93
.32.
Keränen
, J.
, and Hongisto
, V.
(2013
). “Prediction of the spatial decay of speech in open-plan offices
,” Appl. Acoust.
74
, 1315
–1325
.33.
Keränen
, J.
, Virjonen
, P.
, and Hongisto
, V.
(2008
). “Characterization of acoustics in open offices—four case studies
,” in Acoustics'08
, June 29–July 4, Paris, France
, Paper 713.34.
Loewen
, L. J.
, and Suedfeld
, P.
(1992
). “Cognitive and arousal effects of masking office noise
,” Environ. Behav.
24
(3
), 381
–395
.35.
LVI 05-10440
:2010 (2010
). Classification of Indoor Environment 2008
(Rakennustietosäätiö, Helsinki
, Finland
).36.
Moezzi
, M.
, and Goins
, J.
(2011
). “Text mining for occupant perspectives on the physical workplace
,” Build. Res. Inform.
39
(2
), 169
–182
.37.
Pejtersen
, J.
, Allermann
, L.
, Kristensen
, T. S.
, and Poulsen
, O. M.
(2006
). “Indoor climate, psychosocial work environment and symptoms in open-plan offices
,” Indoor Air
16
, 392
–401
.38.
Persson Waye
, K.
, Rylander
, R.
, Benton
, S.
, and Leventhall
, H. G.
(1997
). “Effects of performance and work quality due to low frequency ventilation noise
,” J. Sound Vib.
205
(4
), 467
–474
.39.
Pick
, H. L.
, Siegel
, G. M.
, Fox
, P. W.
, Garber
, S. R.
, and Kerney
, J. K.
(1989
). “Inhibiting the Lombard effect
,” J. Acoust. Soc. Am.
85
(2
), 894
–900
.40.
RIL 243-3
:2008 (2008
). Acoustic Design of Buildings. Offices (in Finnish) (Finnish Association of Civil Engineers, Helsinki, Finland).41.
Ryherd
, E. E.
, and Wang
, L. M.
(2008
). “Implications of human performance and perception under tonal noise conditions on indoor noise criteria
,” J. Acoust. Soc. Am.
124
(1
), 218
–226
.42.
Sakamoto
, S.
, Yokoyama
, S.
, Tsujimura
, S.
, and Tachibana
, H.
(2013
). “Loudness evaluation of general environmental noise containing low frequency components
,” in Proceedings of Internoise 2013
, September 15–18, Innsbruck, Austria
.43.
Tang
, S. K.
, Burnett
, J.
, and Poon
, C. M.
(1996
). “Aural environment in air-conditioned open-plan offices
,” Build. Services Eng. Res. Tech.
17
(2
), 97
–100
.44.
Veitch
, J.
, Bradley
, J.
, Legault
, L.
, Norcross
, S.
, and Svec
, J.
(2002
). “Masking speech in open-plan offices with filtered pink noise noise: Noise level and spectral composition effects on acoustic satisfaction
,” in Internal Report IRC-846
(Institute for Research in Construction
, Ottawa, Canada
).45.
Virjonen
, P.
, Keränen
, J.
, and Hongisto
, V.
(2009
). “Determination of acoustical conditions in open-plan offices—proposal for new measurement method and target values
,” Acta Acust. united Ac.
95
(2
), 279
–290
.46.
Wang
, L. M.
, and Novak
, C. C.
(2010
). “Human performance and perception-based evaluations of indoor noise criteria for rating mechanical system noise with time-varying fluctuations
,” ASHRAE Trans.
116
(2
), 553
–568
.47.
Wang
, Y.
, Leistner
, P.
, and Li
, P.
(2012
). “Objective evaluation of speech intelligibility for speech masked by time reversed masker processed from the target speech and the effects of its parameters
,” Acta Acust. united Ac.
98
, 820
–826
.48.
Watts
, G. R.
, Pheasant
, R. J.
, Horoshenkov
, K. V.
, and Ragonesi
, L.
(2009
). “Measurement and subjective assessment of water generated sounds
,” Acta Acust. united Ac.
95
, 1032
–1039
.49.
Zimmer
, K.
, Ghani
, J.
, and Ellermeier
, W.
(2008
). “The role of task interference and exposure duration in judging noise annoyance
,” J. Sound Vib.
311
, 1039
–1051
.50.
Zwicker
, E.
(1960
). “Ein verfahren zur berechnung der lautstärke” (“A method for calculating the loudness”)
, Acustica
10
(36
), 304
–308
.51.
Zwicker
, E.
(1961
). “Subdivision of the audible frequency range into critical bands (Frequenzgruppen)
,” J. Acoust. Soc. Am.
33
, 248
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