1、 ANSI S12.65-2006 (Revision of ANSI S3.14-1977) AMERICAN NATIONAL STANDARD For Rating Noise with Respect to Speech InterferenceAccredited Standards Committee S12, Noise Standards Secretariat Acoustical Society of America 35 Pinelawn Road, Suite 114E Melville, New York 11747-3177 ANSI S12.65-2006 Rea
2、ffirmed by ANSI March 30, 2011 The 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 an organization
3、 of scientists and engineers formed in 1929 to increase and diffuse the knowledge of acoustics and to promote its practical applications. ANSI S12.65-2006 (Revision of ANSI S3.14-1977) AMERICAN NATIONAL STANDARD For Rating Noise with Respect to Speech InterferenceSecretariat Acoustical Society of Am
4、erica Approved 28 February 2006 American National Standards Institute, Inc. AbstractThis standard defines a simple numerical method for rating the expected speech-interfering aspects of noise using acoustical measurements of the noise. AMERICAN NATIONAL STANDARDS ON ACOUSTICS The Acoustical Society
5、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 committees have wide representation from the technical community (manufacturers, consumers, trade associations, organizatio
6、ns with a general interest, and government representatives). The standards are published by the Acoustical Society of America as American National Standards after approval by their respective Standards Committees and the American National Standards Institute. These standards are developed and publis
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9、ds Committees, and approved as American National Standards by ANSI, the ASA Standards Secretariat arranges for their publication and distribution. An American National Standard implies a consensus of those substantially concerned with its scope and provisions. Consensus is established when, in the j
10、udgment 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 simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered and that a
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12、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 Institute require that action be taken periodically to reaffirm, revise, or withdraw this Standard. Acoustical Society of
13、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 2006 by Acoustical Society of America. This standard may not be reproduced in whole or in part in any form for sale, promotion, or any commercia
14、l 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 request to the Standards Secretariat of the Acoustical Society of America.Contents1 Scope . 12 Normative references. 13 Terms an
15、d definitions. 14 Nomenclature . 25 Application of the speech interference level. 25.1 Rank-ordering of noises with respect to speech interference. 25.2 Face-to-face communication. 2FiguresFigure 1 Talker-to-listener distances for just-reliable communication 4Foreword This Foreword is for informatio
16、n only, and is not a part of the American National Standard ANSI S12.65 - 2006 American National Standard For Rating Noise with Respect to Speech Interference.This standard comprises a part of a group of definitions, standards, and specifications for use in noise. It was developed and approved by Ac
17、credited Standards Committee S12 Noise, under its approved operating procedures. Those procedures have been accredited by the American National Standards Institute (ANSI). The Scope of Accredited Standards Committee S12 is as follows: Standards, specifications, and terminology in the field of acoust
18、ical noise pertaining to methods of measurement, evaluation, and control; including biological safety, tolerance, and comfort, and physical acoustics as related to environmental and occupational noise.This standard is a revision and redesignation of ANSI S3.14-1977. In this revision the normative re
19、ferences have been updated, some new bibliographic references have been added as well as some introductory material about Speech Transmission Index (STI), Rapid Speech Transmission Index (RASTI), Articulation Index (AI), and Percent Loss of Consonants (%ALCONS), although these are not included in th
20、is standard. The definition of speech interference level has also been updated to be consistent with ANSI S1.1-1994.This standard is not comparable to any existing ISO Standard At the time this Standard was submitted to Accredited Standards Committee S12, Noise for approval, the membership was as fo
21、llows: R.D. Hellweg, ChairR.D. Godfrey, Vice-ChairS.B. Blaeser, SecretaryAcoustical Society of AmericaB.M. Brooks P.D. Schomer (Alt.) Aearo Company.E.H. BergerAir-Conditioning and Refrigeration Institute .R. Seel . D. Brown (Alt.) Alcoa, Inc. W.D. Gallagher American Industrial Hygiene Association. D
22、. DriscollJ. Banach (Alt.) American Society of Heating, Refrigeration, and Air-Conditioning R.J. PeppinE. Rosenberg (Alt.) American Speech-Hearing-Language Association .L.A. Wilber. V. Gladstone (Alt.) Bruel FAX: 631-390-0217; E-mail: asastdsaip.orgivIntroductionThe intelligibility of speech in nois
23、e is dependent on many factors. These include: (1) Acoustic factors, such as the level of the speech signal (at the listeners ear), the level of the interfering noise, the frequency spectrum of the speech signal, the frequency spectrum of the noise, the temporal pattern of the speech and noise, diff
24、erences in the spatial relationship of the speech and noise sources, and reverberation effects. (2) Nonacoustic factors, such as size of message set, a priori probability of occurrence of each message or unit of speech, the listeners motivation and familiarity with the speech material, the role of v
25、isual cues, and the talkers speech habits. (3) Random or quasirandom factors, such as individual differences between talkers and listeners, day-to-day variations in a listeners ability or a talkers effectiveness, effects of randomization in the choice of test material, and random sampling errors. NO
26、TE The deleterious effect of noise on speech intelligibility may be greater for elderly listeners or listeners with sensory neural hearing impairments. The method in which intelligibility is specified depends on the testing procedure. Subjective testing procedures that are commonly used yield senten
27、ce intelligibility 2, 8, monosyllabic word intelligibil-ity or scores from a checklist of response words, such as the modified rhyme test 13 see American National Standard S3.2-1989 (R1999). Ideally, given information on all of the above factors and the method for specifying intelligibility, it shou
28、ld be possible to predict accurately the intelligibility of speech in noise. There are, however, basic limitations to the accuracy of such predictions. First, the abovementioned random factors set an upper bound on precision. Second, not all the factors affecting intelligibility are fully understood
29、. Experiments have shown, however, that reasonably accurate predictions of intelligibility can be made from acoustical measurements of the speech and the noise, given detailed information on the method of testing, speech material, skill and motivation of the listeners, and the proficiency of the tal
30、ker 10, 18, 20, 27. In addition, there are several measurements which provide estimates of speech intelligibility by characterizing the noise and reverberation in a room. These include, Speech Transmission Index (STI), Rapid Speech Transmission Index (RASTI), Articulation Index (AI), Speech Intellig
31、ibility Index (SII), Percent Loss of Consonants (%ALCONS) 7, 15, 23, 26, 29. It is important to recognize the distinction between the physical measure called speech interference level and its application. The definition of speech interference level is exact; it is based on acoustical measurements of
32、 the noise and is specified with the same precision required of any physically measurable standard. The application of the index, e.g., as a predictor of speech interference, is less precise, owing to the limitations listed above. This is a difficulty common to all measures or standards attempting t
33、o predict perceptual effects. This does not mean that reasonably accurate predictions of subjective quantities cannot be made, but only that there is a substantial difference in the degree of precision that can be obtained. Experimental data on the relative precision of the speech interference level
34、 and other predictors of speech interference may be found in 4- 6, 16-22, 24, 25, 27, 28, 30-39. Finally, it should be recognized that this standard is applicable to natural speech. Speech that is electronically transmitted, either in analog or digital form, or is electronically reinforced can be su
35、bject to distortion, both linear and nonlinear which can degrade its intelligibility beyond that which would be predicted by the speech interference level. Application of the SIL to predict intelligibility in these cases may be misleading. vAMERICAN NATIONAL STANDARD ANSI S12.65-2006American Nationa
36、l Standard For Rating Noise with Respect to Speech Interference1 Scope This standard defines a simple numerical method for rating the expected speech-interfering aspects of noise using acoustical measurements of the noise. The relevant acoustical characteristics of the noise are summarized in terms
37、of a single-valued index known as the speech interference level. The application of the measure is intended for natural speech. NOTE The speech interference level is related to the speech intelligibility index (ANSI S3.5-1997 (R2002) and to A-weighted sound level (ANSI S1.42-2001 (R 2006). 2 Normati
38、ve references The following referenced documents are indispensable for the application of this standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ANSI S1.1-1994 (R 2004), American N
39、ational Standard Acoustical Terminology.ANSI S1.4-1983 (R 2006) with Amd.S1.4A-1985 (R 2006), American National Standard Specification for Sound Level Meters.ANSI S1.11-2004, American National Standard Specification for Octave-Band and Fractional-Octave-Band Analog and Digital Filters.ANSI S3.2-1989
40、 (R1999), American National Standard Method for Measuring the Intelligibility of Speech over Communication Systems. ANSI S3.5-1997 (R2002), American National Standard Methods for the Calculation of the Speech Intelligibility Index.3 Terms and definitions For the purposes of this standard, the terms
41、and definitions given in ANSI S1.1-1994 (R 2004) and the following apply: 3.1 speech interference level. One-fourth of the sum of the band sound pressure levels for octave-bands with normal midband frequencies of 500, 1000, 2000, and 4000 Hz. Unit, decibel; abbreviation, SIL; symbol LSI.NOTE 1 The l
42、imiting frequencies for the four octave bands cited above are 355-710, 710-1400, 1400-2800, and 2800-5600 Hz, respectively. In practice, these octave bands are realized with filters conforming to American National Standard S1.11-2004. NOTE 2 In the previous edition (ANSI S3.14-1977) this symbol was
43、LSIL. Acoustical Society of America, 2006. 1ANSI S12.65-20064 Nomenclature A precise abbreviation for the speech interference level is SIL (0.5, 1, 2, 4). This complete abbreviation has been recommended in the past because several different versions of speech inter-ference level based on other octav
44、e bands have been used in the past 1, 32. When there is no likelihood of confusion between this index and an index based on other octave bands, then the shorter abbreviation SIL may be used. For cases where other octave bands have been used, the numbers in parentheses should indicate the center freq
45、uencies of the bands used. For example, SIL (1, 2, 4) indicates the average SPL of the octave bands at center frequencies of 1000, 2000, and 4000 Hz, respectively. Among the various definitions of speech interference level that have been used in the past is the one proposed originally by Beranek 1,
46、32 in which the three contiguous octave bands covering the range from 600 to 4800 Hz were used. In another version of this index 32 referred to as the preferred speech interference level (PSIL), the three octave bands centered on 500, 1000, and 2000 Hz, respectively, were used. The effects of using
47、different octave bands in the determination of speech interference level are discussed in references 32, 35, and 36. 5 Application of the speech interference level Two possible applications of the speech interference level are given below. The more precise application is described first. 5.1 Rank-or
48、dering of noises with respect to speech interference An important practical property of the speech interference level is that noises having the same speech interference level reduce speech intelligibility by roughly the same amount. That is, two or more noises having the same speech interference lev
49、el result in approximately the same intelligibility score, all other factors being equal. Measurements of the distribution of speech interference levels for a number of equally interfering noises showed a standard deviation of less than 3 dB among noises 16, 31. Using these data as a guide, one may rank-order different noises according to their speech interference level. If the speech interference level for one noise is greater than that of a second noise by more than 5 dB, then, in the absence of contrary evidenc
