1、 ANSI/ASA S12.2-2008 (Revision of ANSI S12.2-1995) AMERICAN NATIONAL STANDARD Criteria for Evaluating Room Noise Accredited Standards Committee S12, Noise Standards Secretariat Acoustical Society of America 35 Pinelawn Road, Suite 114 E Melville, NY 11747-3177ANSI/ASAS12.2-2008 The American National
2、 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 of scientists and engineers formed in 1929 to incre
3、ase and diffuse the knowledge of acoustics and to promote its practical applications. ANSI/ASA S12.2-2008 (Revision of ANSI S12.2-1995) AMERICAN NATIONAL STANDARD Criteria for Evaluating Room Noise Secretariat: Acoustical Society of America Approved July 3, 2008 by: American National Standards Insti
4、tute, Inc. Abstract This Standard provides three primary methods for evaluating room noise: a survey method that employs the A-weighted sound level; an engineering method that employs expanded noise criteria (NC) curves; and a method for evaluating low-frequency fluctuating noise using room noise cr
5、iterion (RNC) curves. 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, S3/SC 1 on Animal Bioacoustics, and S12 on Noise. These commi
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11、han a 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
12、, whether 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 NOTICE: This American National Standard may be revised or withdrawn at any time.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 Stan
13、dards 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 2008 by Acoustic
14、al Society 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
15、request to the Standards Secretariat of the Acoustical Society of America.iContents 1 Scope . 1 2 Normative references. 2 3 Terms, definitions, abbreviations, and symbols . 2 4 Significance and use of this Standard and deviations from the previous ANSI S12.2-1995 . 4 5 Criteria 6 5.1 A-weighted crit
16、eria 6 5.2 NC (noise criteria) curves . 6 5.3 RNC (room noise criterion) .10 6 Acoustically induced vibrations and rattles 17 Annex A (informative) Example evaluations using RNC . 18 A.1 Evaluation of room noise using the RNC curves 18 A.2 Example 1 Excessive turbulence (large standard deviation) an
17、d minimal surging 18 A.3 Example 2 Strong surging and strong turbulence 21 Annex B (informative) A discussion of the criteria. 24 B.1 Discussion of RC, NC, and NCB criteria curves . 24 B.2 Discussion of RNC criteria curves 25 Annex C (informative) Recommended noise level criteria for various occupie
18、d activity areas. 26 C.1 Recommended A-weighted criteria. 26 C.2 Recommended NC and RNC criteria 27 Annex D (informative) RC Mark II 30 D.1 Introduction . 30 D.2 Room criterion curves . 30 D.3 Spectrum classification . 30 D.4 Method for calculating an RC value 33 D.5 Quality assessment index (QAI) .
19、 33 D.6 Recommended criteria33 Annex E (informative) Criteria for recording studios and other low-noise situations. 35 E.1 Criteria. 35 E.2 Recording studio “audibility“ threshold curves 35 Bibliography. 37 Tables Table 1 Octave-band sound levels to the nearest decibel for noise criteria curves 15,
20、p. 893 7 ii Table 2 Measured sound pressure deviations from an NC (SIL) curve that may lead to serious complaints 9 Table 3 Screening criteria to determine the presence of large random fluctuations 11 Table 4 Octave-band sound pressure levels to the nearest decibel for room noise criteria curves 10
21、. 11 Table 5 Coefficients to calculate an RNC value from a given octave-band level, or an octave-band level from a given RNC value see Eqs. (1) and (2). 13 Table 6 Measured sound pressure levels for perceptible vibration and rattles in lightweight wall and ceiling structures 17 Table A.1 This table
22、shows the first 5 samples for Example 1. 19 Table A.2 This table contains the summary data for Example 1 19 Table A.3 These data represent artificially generated Gaussian noise. This table shows the first 20 samples for Example 2. The sample period is 100 ms and the octave-band levels are fast-time
23、weighted. The OASPL has been calculated as the energy sum of the 10 indicated octave-band levels. The “3-band sum” is the energy sum of the 16, 31.5, and 63-Hz octave-band levels after 14 dB have been subtracted from the 16-Hz octave-band levels and 14 dB have been added to the 63-Hz octave-band lev
24、els. Surging has been implemented as a sine wave with a 2-s period and a 15-dB peak-to-peak amplitude. 21 Table A.4 This table contains the summary data for Example 2. The LEQ is the energy average for all time samples represented by the indicated column. The 3-band sum correction of 11.3 dB is adde
25、d to the 31.5-Hz octave band LEQ and the 1.6-dB correction at 125 Hz is added to the LEQ in this octave band. Therefore, the reported adjusted 31.5-Hz octave-band level is 73.1 (the LEQ of 61.8 in the 31.5-Hz octave band plus the adjustment of 11.3 dB). The reported level in the 125-Hz octave band i
26、s just the 125-Hz LEQ plus 1.6. 22 Table C.1 A-weighted (unoccupied) sound level criteria for rooms of various uses 15, p. 890 . 26 Table C.2 NC and RNC (unoccupied) criteria values for rooms of various uses 15, p. 891 27 Table D.1 Mark II room criteria (RC) curves. 31 Table D.2 RC criteria for vari
27、ous activity areas excluding the noise due to human occupancy. The (N) stands for a neutral spectrum as defined in Clause D.3.1. 34 Table E.1 Recording studio “audibility“ threshold for one-third octave bands see 8 . 36 Figures Figure 1 Noise criteria (NC) curves The example shows an NC-51 (125 Hz)
28、spectrum. 8 Figure 2 Room noise criteria (RNC) curves 12 Figure A.1 The spectrum of Example 1 plotted on the RNC curves. In this example sound exhibits no surging, but it does include large turbulence. The standard deviation of the sound level in the 3-band sum combined 16, 31.5 and 63-Hz octave ban
29、ds is 3.2 dB. Using the tangent method, the iiihighest RNC curve is contacted by the 31.5-Hz octave band and has a value of RNC-40. So this spectrum is reported as an RNC-40 (31.5 Hz). The correction factor of 3.6 dB that is added to the measured LEQ in the 31-Hz octave band changes this spectrum fr
30、om an RNC-31 (8 kHz) to an RNC-40 (31.5 Hz). 20 Figure A.2 The spectrum of Example 2 plotted on the RNC curves. In this example sound exhibits 15-dB peak-to-peak sinusoidal surging and large turbulence. The standard deviation of the sound level in the 3-band sum combined 16, 31.5 and 63-Hz octave ba
31、nds is 3.1 dB. Using the tangent method, the highest RNC curve is contacted by the 31.5-Hz octave band and has a value of RNC-44. So this spectrum is reported as an RNC-44 (31.5 Hz). The correction factor of 11.3 dB that is added to the measured LEQ in the 31.5-Hz octave band changes this spectrum f
32、rom an RNC-25 (250 Hz) to an RNC-44 (31.5 Hz). 23 Figure D.1 Mark II room criteria curves 32 iv Foreword This Foreword is for information only and is not a part of the American National Standard ANSI/ASA S12.2-2008 American National Standard Criteria for Evaluating Room Noise. This standard comprise
33、s a part of a group of definitions, standards, and specifications for use in noise. It was developed and approved by Accredited Standards Committee S12, Noise, under its approved operating procedures. Those procedures have been accredited by the American National Standards Institute (ANSI). The Scop
34、e of Accredited Standards Committee S12 is as follows: Standards, specifications, and terminology in the field of acoustical noise pertaining to methods of measurement, evaluation, and control; including biological safety, tolerance, and comfort, and physical acoustics as related to environmental an
35、d occupational noise. This standard is a revision of ANSI S12.2-1995, which has been technically revised. The NCB has been replaced by NC curves that have been extended down to 16 Hz, which makes them nearly the same as the NCB curves. The RC procedures of the 1995 edition now also are presented bri
36、efly in an informative Annex. This new Standard provides three primary methods for evaluating room noise: a survey method that employs the A-weighted sound level; an engineering method that employs expanded noise criteria (NC) curves; and a method for evaluating low-frequency fluctuating noise using
37、 room noise criterion (RNC) curves. 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 follows: R.D. Hellweg, Chair W.J. Murphy, Vice-Chair S.B. Blaeser, Secretary Aco
38、ustical Society of AmericaB.M. Brooks Aearo Company.E.H. Berger Air-Conditioning and Refrigeration Institute .R. Seel . D. Brown (Alt.) Alcoa, Inc. W.D. Gallagher American Industrial Hygiene Association. D. Driscoll .S.N. Hacker (Alt.) American Society of Heating, Refrigeration and Air-Cond R.J. Pep
39、pin E. Rosenberg (Alt.) American Speech-Language -Hearing Association L.A. Wilber . V. Gladstone (Alt.) Bruel FAX: 631-390-0217; E-mail: asastdsaip.org. AMERICAN NATIONAL STANDARD ANSI/ASA S12.2-2008 2008 Acoustical Society of America All rights reserved 1American National Standard Criteria for Eval
40、uating Room Noise 1 Scope This Standard provides three primary methods for evaluating room noise: a survey method, an engineering method, and a method for evaluating low-frequency fluctuating noise. Two methods for evaluating room noiseRC (room criterion) and NCB (balanced noise criterion) curveswer
41、e the basis of the previous ANSI S12.2-1995 standard, and RC is included briefly for informational purposes in Annex D. All of the methods assume that the measured noise is free of tones. (ANSI S1.13-2005 Annex A gives an accurate method for assessing the presence of prominent discrete tones using n
42、arrow band analysis.) The three primary methods are: 1. The survey method that employs the A-weighted sound level; 2. The engineering method that employs noise criteria (NC) curves; and 3. The method for evaluating low-frequency fluctuating noise using room noise criteria (RNC) curves. This Standard
43、 also contains one ancillary set of criteria curves for evaluating acoustically induced vibrations or rattles. Requirements are given in the body of the Standard for determining whether a: 1. Measured or estimated A-weighted sound level satisfies a specified noise criterion. 2. Set of octave-band so
44、und pressure levels satisfies a specified noise criterion (NC) curve. 3. Time-series of octave-band sound pressure levels satisfies a specified room noise criterion (RNC) curve. 4. Table of octave-band sound pressure levels that, when modulated by fluctuations at low frequencies, may cause perceptib
45、le vibrations or rattles in lightweight constructions. Annex A presents examples of the use of RNC for evaluating measured or estimated sound level spectra in rooms. Annex B presents a discussion of RC, NC, NCB, and RNC curves. Annex C contains recommended noise level specifications for various occu
46、pied activity areas. Annex D contains the procedures for use of the room criteria (RC) curves. Annex E contains criteria for recording studios and other low-noise situations. ANSI/ASA S12.2-2008 2008 Acoustical Society of America All rights reserved 2 No guidance is given for the selection of equipm
47、ent or the methods for measuring noise levels to be evaluated by the curves. 2 Normative 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 refer
48、enced document (including any amendments) applies. ANSI S1.1-1994 (R 2004) American National Standard Acoustical Terminology. ANSI S1.4-1983 (R 2006) American National Standard Specification for Sound Level Meters. ANSI S1.4A-1985 (R 2006) Amendments to ANSI S1.4-1983. ANSI S1.6-1984 (R 2006) Americ
49、an National Standard Preferred Frequencies, Frequency Levels, and Band Numbers for Acoustical Measurements. ANSI S1.13-2005 American National Standard Measurement of Sound Pressure Levels in Air. ANSI S12.65-2006 American National Standards Rating Noise with Respect to Speech Interference. 3 Terms, definitions, abbreviations, and symbols For the purposes of this standard, the terms and definitions given in ANSI S1.1-1994 and the following apply: 3.1 mid-frequency average (LMF) the average of the octave-band sound pressu
