1、ANSI S3.4-2007(Revision of ANSI S3.4-2005) AMERICAN NATIONAL STANDARDProcedure for the Computation of Loudness of Steady Sounds Accredited Standards Committee S3, BioacousticsStandards Secretariat Acoustical Society of America 35 Pinelawn Road, Suite 114E Melville, NY 11747-3177 ANSI S3.4-2007 Reaff
2、irmed by ANSI June 15, 2012 5HDIILUPHGE$16,-XOThe American National Standards Institute, Inc. (ANSI) is the national coordinator of voluntary standards development and the clearinghouse in the U.S.A. for information on national and international standards. The Acoustical Society of America (ASA) is
3、an organization of scientists and engineers formed in 1929 to increase and diffuse the knowledge of acoustics and to promote its practical applications. ANSI S3.4-2007 (Revision of ANSI S3.4-2005) AMERICAN NATIONAL STANDARD Procedure for the Computation of Loudness of Steady Sounds Secretariat Acous
4、tical Society of America Approved: May 24, 2007 American National Standards Institute, Inc. Abstract This standard specifies a procedure for calculating the monaural and binaural loudness of steady sounds as perceived by listeners with normal hearing. The procedure is based on the spectra of the sou
5、nds. The possible sounds include simple and complex tones (both harmonic and inharmonic), bands of noise and mixtures of tones and noise. The spectra can be specified exactly, in terms of the frequencies and levels of individual spectral components, or approximately, in terms of the levels in 1/3 oc
6、tave bands covering center frequencies from 50 to 16,000 Hz. The standard is applicable to sounds presented in free field with a frontal incidence, in a diffuse field, or listening via headphones. The procedure is available as a computer program that provides the loudness level in phons and the corr
7、esponding loudness estimate in sones. Examples of the estimates generated by the program for a variety of input spectra are presented in Annex A. The software for calculation of loudness according to ANSI S3.4-2007 is described in Annex B. It accompanies the standard for the convenience of the purch
8、aser. Use of this software is not required for conformance. AMERICAN NATIONAL STANDARDS ON ACOUSTICS The Acoustical Society of America (ASA) provides the Secretariat for Accredited Standards Committees S1 on Acoustics, S2 on Mechanical Vibration and Shock, S3 on Bioacoustics, and S12 on Noise. These
9、 committees have wide representation from the technical community (manufacturers, consumers, trade associations, organizations with a general interest, and government representatives). The standards are published by the Acoustical Society of America as American National Standards after approval by t
10、heir respective Standards Committees and the American National Standards Institute. These standards are developed and published as a public service to provide standards useful to the public, industry, and consumers, and to Federal, State, and local governments. Each of the accredited Standards Commi
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13、implies a consensus of those substantially concerned with its scope and provisions. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a
14、 simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered and that a concerted effort be made towards their resolution. The use of an American National Standard is completely voluntary. Their existence does not in any respect preclude anyone, whe
15、ther he or she has approved the Standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the Standards. NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards
16、 Institute require that action be taken periodically to reaffirm, revise, or withdraw this Standard. Acoustical Society of America ASA Secretariat 35 Pinelawn Road, Suite 114E Melville, New York 11747-3177 Telephone: 1 (631) 390-0215 Fax: 1 (631) 390-0217 E-mail: asastdsaip.org 2007 by Acoustical So
17、ciety of America. This standard may not be reproduced in whole or in part in any form for sale, promotion, or any commercial purpose, or any purpose not falling within the provisions of the U.S. Copyright Act of 1976, without prior written permission of the publisher. For permission, address a reque
18、st to the Standards Secretariat of the Acoustical Society of America. 2007 Acoustical Society of America. All rights reserved. iContents 1 Scope . 1 2 Terms and definitions. 1 3 Procedure. 3 3.1 Introduction. 3 3.2 Specification of input signal 3 3.3 Transfer function to take into account transfer t
19、o the eardrum 4 3.4 Transfer function to take into account transmission through the middle ear . 5 3.5 Transformation of spectrum to excitation pattern. 10 3.6 Transformation from excitation to specific loudness 16 3.7 Summation of specific loudness across frequency 24 3.8 Monaural versus binaural l
20、oudness (diotic and dichotic stimuli) 24 3.9 Conversion from phons to sones . 24 3.10 Calculation of absolute threshold. 24 Annex A (informative) Sample results using ANSI S3.4-2007 27 A.1 Sinusoidal tones. 27 A.2 Filtered noise 28 A.3 Multiple tones . 29 A.4 Tones plus noise 30 Annex B (informative
21、) Software for calculation of loudness according to ANSI S3.4-2007 31 Tables Table 1 Free field to eardrum transfer function (frontal incidence). The first column specifies the frequency (Hz) and the second column specifies the level at the eardrum minus the level measured in the free field (in the
22、absence of a listener), in dB 6 Table 2 Diffuse field to eardrum transfer function. The first column specifies the frequency (Hz) and the second column specifies the level at the eardrum minus the level measured in the diffuse field (in the absence of a listener), in dB 8 Table 3 Transfer function o
23、f middle ear. The first column specifies the frequency (Hz) and the second column specifies the effective level at the cochlea, relative to the level at the eardrum, in dB. Values in italics are in a range that has not been validated. . 12 Table 4 Internal excitation level at threshold for monaural
24、listening. The first column shows the center frequency (Hz) and the second column shows the excitation level in dB. The value is constant for all frequencies above 500 Hz. 17 Table 5 Value of the parameter (alpha) as a function of the parameter G (dB) 20 Table 6 Value of the parameter A as a functio
25、n of the parameter G (dB) 21 Table 7 Relationship between loudness level in phons and loudness in sones. Values in italics are given for completeness, but have not been validated 25 2007 Acoustical Society of America. All rights reserved. ii Figures Figure 1 Free field to eardrum transfer function.
26、The level at the eardrum minus the level measured in the free field (in the absence of a listener) is plotted as a function of frequency in kHz 7 Figure 2 Diffuse field to eardrum transfer function. The level at the eardrum minus the level measured in the diffuse field (in the absence of a listener)
27、 is plotted as a function of frequency in kHz. 9 Figure 3 Transfer function of middle ear (dB) plotted as a function of frequency in kHz. The dashed line indicates a range that has not been validated. 13 Figure 4 The shape of the auditory filter centered at 1 kHz for input levels/ ERBNfrom 20 to 100
28、 dB in 10-dB steps. The output level in dB of the filter is plotted as a function of frequency of the input in kHz. 14 Figure 5 Excitation patterns for 1-kHz sinewaves with levels ranging from 20 to 100 dB in 10-dB steps. The frequency scale has been transformed to an ERBN-number scale, as defined b
29、y Equation 4. The lower abscissa shows the ERBN-number. The corresponding frequency in Hz is shown at the top. 15 Figure 6 Internal excitation level at threshold for monaural listening in dB, plotted as a function of center frequency in kHz. The value is constant for all frequencies above 0.5 kHz. 1
30、7 Figure 7 Value of the parameter (alpha) as a function of the parameter G (dB). 20 Figure 8 Value of the parameter A as a function of the parameter G (dB). 22 Figure 9 The transformation from excitation level in dB to specific loudness, with the excitation level at absolute threshold (ETHRQconverte
31、d to decibels) as parameter. The curve labeled 3.6 applies for all center frequencies above 500 Hz. Other curves are for values of the excitation level at absolute threshold of 6.3, 14.5, 20.2 and 26.2 dB, corresponding to center frequencies of 253, 108, 74 and 52 Hz, respectively. The dashed line i
32、ndicates a range, above 100 dB, that has not been validated 23 Figure 10 Value of loudness in sones as a function of the loudness level in phons. The dashed line indicates a range, above 100 phons, that has not been validated. 26 2007 Acoustical Society of America. All rights reserved. iiiForeword T
33、his Foreword is for information only, and is not a part of the American National Standard ANSI S3.4-2007 American National Standard Procedure for the Computation of Loudness of Steady Sounds. This standard comprises a part of a group of definitions, standards, and specifications for use in bioacoust
34、ics. It was developed and approved by Accredited Standards Committee S3 Bioacoustics, under its approved operating procedures. Those procedures have been accredited by the American National Standards Institute (ANSI). The Scope of Accredited Standards Committee S3 is as follows: Standards, specifica
35、tions, methods of measurement and test, and terminology in the fields of psychological and physiological acoustics, including aspects of general acoustics, which pertain to biological safety, tolerance and comfort. This standard is a revision of ANSI S3.4-2005, which was in turn a revision of ANSI S
36、3.4-1980. Loudness is the perceived intensity of a sound (see below for definition). Loudness depends on both the acoustic properties of the sound that impinges on a listener and on the listener. This standard gives an estimate of the loudness of steady sounds as perceived by normally hearing listen
37、ers under specified conditions. The recommended procedure is based on a model of loudness perception (Moore, Glasberg, and Baer, 1997; Glasberg and Moore, 2006) that was developed from a model originally proposed by Zwicker and his co-workers (1958, 1965, 1984, 1999). Zwickers model is part of ISO 5
38、32:1975. These models have their roots in the pioneering work of Fletcher and Munson (1933). The current procedure extends and improves the accuracy of these earlier methods. It replaces the more limited computational procedure used in the old ANSI S3.4-1980 that was based on the method proposed by
39、S.S. Stevens (1957, 1961). Unlike the old ANSI S3.4-1980, the current standard can be applied to sounds with sharp line spectral components, e.g., transformer hum or fan noise, as well as to sounds with broadband spectra. Provided the measurement of sound pressure levels is sufficiently precise, and
40、 subject to certain restrictions specified below, the recommended procedure may also be used to estimate loudness, or loudness level, with reasonable accuracy down to near threshold levels. Moreover, it enables the loudness of complex sounds containing spectral energy below 500 Hz to be determined.
41、The equal-loudness contours derived from this standard are in good agreement with ISO 226:2003 (see also Suzuki and Takeshima, 2004). Because loudness is a subjective quantity, the perception of which may vary among people, any calculated loudness value represents only an estimate of the average lou
42、dness as perceived by a group of individuals with normal hearing. The changes made in this revision are: (1) A modification to the method for calculating specific loudness from excitation for center frequencies below 500 Hz to make the standard fully compatible with the provided software and with th
43、e model of Moore et al. (1997) and with its amendment by Glasberg and Moore (2006); (2) A modification to the transfer function of the middle ear, as proposed by Glasberg and Moore (2006), which allows more accurate predictions of the absolute thresholds in ISO 389-7:2005 and of the equal-loudness c
44、ontours in ISO 226:2003. The software provided with this American National Standard is entirely informative and provided for the convenience of the user. Use of the provided software is not required for conformance with the Standard. ASA and the owners of the copyright to the software provided with
45、this American National Standard make no other representation or warranty or condition of any kind, whether express or implied (either in fact or by operation of law) with respect to any part of the product, including, without limitation, with respect to the sufficiency, accuracy or utilization of, o
46、r any information or opinion contained or reflected in, any of the product. ASA and the owner expressly disclaim all warranties or conditions of merchantability or fitness for a particular purpose. No officer, director, employee, member, agent, 2007 Acoustical Society of America. All rights reserved
47、. iv representative or publisher of the copyright holder is authorized to make any modification, extension, or addition to this limited warranty. At the time this Standard was submitted to Accredited Standards Committee S3, Bioacoustics for approval, the membership was as follows: C.A. Champlin, Cha
48、ir R.F. Burkard, Vice-Chair S.B. Blaeser, Secretary Acoustical Society of America . C.A. Champlin R.F. Burkard (Alt.) American Academy of Audiology .Y. Szymko-Bennett D.A. Fabry (Alt.) American Academy of Otolaryngology, Head and Neck Surgery, Inc. . .R.A. Dobie . L.A. Michael (Alt.) American Indust
49、rial Hygiene Association T.K. Madison . D. Driscoll (Alt.) American-Speech-Language-Hearing Association (ASHA) L.A. Wilber V. Gladstone (Alt.) Beltone/GN Resound S. Petrovic Council for Accreditation in Occupational Hearing Conservation (CAOHC) .E.H. Berger .J.A. Mann (Alt.) Etymotic Research, Inc. M.C. Killion .R. Scicluna (Alt.) Food and Drug Administration J. Kane Frye Electronics, Inc. G.J. Frye K.E. Frye (Alt.) Hearing Industries Association .T.A. Victorian .C.M. Rogin (Alt.) Nati
