1、 ANSI/ASA S3.7-2016 AMERICAN NATIONAL STANDARD Method for Measurement and Calibration of Earphones Accredited Standards Committee S3, Bioacoustics Standards Secretariat Acoustical Society of America 1305 Walt Whitman Road, Suite 300 Melville, NY 11747ANSI/ASAS3.7-2016 The American National Standards
2、 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 increase and di
3、ffuse the knowledge of acoustics and to promote its practical applications. ANSI/ASA S3.7-2016 (Revision of ANSI/ASA S3.7-1995 (R2008) AMERICAN NATIONAL STANDARD Method for Measurement and Calibration of Earphones Secretariat: Acoustical Society of America Approved on August 22, 2016, by: American N
4、ational Standards Institute, Inc. ABSTRACT This standard describes measurement methods for earphones and earphone transducers using couplers or ear simulators. Guidance is provided for the selection of the appropriate coupler or ear simulator for a given earphone and application. Methods for measure
5、ment of calibrated frequency response, input-output linearity, electrical impedance, and non-linear distortion, are described. 2 2016 Acoustical Society of America All Rights Reserved AMERICAN NATIONAL STANDARDS ON BIOACOUSTICS The Acoustical Society of America (ASA) provides the Secretariat for Acc
6、redited 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 committees have wide representation from the technical community (manufacturers, consumers, trade associations, organizations with a general
7、 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 (ANSI). These standards are developed and published as a p
8、ublic service to provide standards useful to the public, industry, and consumers, and to Federal, State, and local governments. Each of the Accredited Standards Committees (operating in accordance with procedures approved by ANSI) is responsible for developing, voting upon, and maintaining or revisi
9、ng its own Standards. The ASA Standards Secretariat administers Committee organization and activity and provides liaison between the Accredited Standards Committees and ANSI. After the Standards have been produced and adopted by the Accredited Standards Committees, and approved as American National
10、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 judgment of the ANSI Board of Standards Review, su
11、bstantial 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 concerted effort be made towards their resolution
12、. The use of an American National Standard is completely voluntary. Their existence does not in any respect preclude anyone, 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. NO
13、TICE: 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 America ASA Secretariat 1305 Walt Whitman Road, S
14、uite 300 Melville, New York 11747 Telephone: 1 (631) 390-0215 Fax: 1 (631) 923-2875 E-mail: asastdsacousticalsociety.org 2016 by Acoustical 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 falli
15、ng 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.ANSI/ASA S3.7-2016 2016 Acoustical Society of America All Rights Reserved i Contents 1 Sc
16、ope . 1 2 Normative references 1 3 Terms and definitions 2 4 Coupler / ear simulator selection . 3 4.1 General . 3 4.2 Earphone types . 4 5 Measurements of earphone response . 5 5.1 Overview . 5 5.2 Standard ambient reference conditions 5 5.3 Measurement system and test environment 5 5.4 Mounting th
17、e earphone or receiver on the coupler or ear simulator 6 5.5 Frequency response . 7 5.6 Input/output characteristic 9 5.7 Electrical impedance. 10 5.8 Harmonic distortion . 12 Annex A (informative) Test configurations for various insert earphone types . 16 A.1 Acoustic connection to the coupler or e
18、ar simulator . 16 A.2 The HA-1 configuration . 16 A.3 The HA-2 configuration . 17 A.4 The HA-2B configuration 18 A.5 The HA-3 configuration . 18 A.6 The HA-4 configuration . 19 Annex B (informative) Two-tone distortion measurements 21 B.1 Difference frequency distortion . 21 B.2 Procedure for measur
19、ing difference frequency distortion . 22 B.3 Intermodulation distortion . 24 B.4 Procedure for measuring intermodulation distortion . 24 Annex C (informative) Left-right tracking response for stereo earphones . 27 Annex D (informative) Tolerances and measurement uncertainty . 28 Bibliography . 30 ii
20、 2016 Acoustical Society of America All Rights Reserved Figures Figure 1 High- and low-acoustic-impedance earphones. . 4 Figure 2 Earphone types with respect to coupling to the outer ear. . 4 Figure 3 Test system configuration for earphone or receiver measurements. . 5 Figure 4 Example of an earphon
21、e frequency response. . 8 Figure 5 Example of earphone input/output characteristics at several frequencies, showing fundamentals and corresponding total distortion. . 10 Figure 6 Electrical impedance test circuit using a series detection resistor. 11 Figure 7 Example of the impedance magnitude of an
22、 earphone. . 12 Figure 8 Example of Total Harmonic Distortion of an earphone. 14 Figure 9 Example of Fundamental and Harmonics of an earphone. 15 Figure A.1 HA-1 configuration. 16 Figure A.2 HA-2 configuration. 17 Figure A.3 HA-2B configuration. . 18 Figure A.4 HA-3 configuration. 19 Figure A.5 HA-4
23、 configuration. 20 Figure B.1 Definition of difference frequency distortion products and orders. 21 Figure B.2 Example of Difference Frequency Distortion of an earphone. 22 Figure B.3 Example of Total Difference Frequency Distortion of an earphone. . 23 Figure B.4 Definition of intermodulation disto
24、rtion products and orders. 24 Figure B.5 Example of Intermodulation Distortion of an earphone. 25 Figure B.6 Example of Total Intermodulation Distortion of an earphone. . 26 Figure C.1 Example of a Left-Right Tracking Response for a stereo earphone. 27 Figure D.1 Relationship between tolerance limit
25、s, corresponding acceptance intervals and the maximum permitted uncertainty of measurement, UMAX. 28 ANSI/ASA S3.7-2016 2016 Acoustical Society of America All Rights Reserved iii Tables Table 1 Couplers and ear simulators, associated standards, and earphone applications. 3 Table 2 Decibel conversion
26、 to and from MKS (SI) units. 9 Table D.1 Example uncertainty budget . 29 iv 2016 Acoustical Society of America All Rights Reserved Foreword This Foreword is for information only and is not a part of the American National Standard ANSI/ASA S3.7-2016 American National Standard Method for Measurement a
27、nd Calibration of Earphones. As such, this Foreword may contain material that has not been subjected to public review or a consensus process. In addition, it does not contain requirements necessary for conformance to the standard. This standard comprises a part of a group of definitions, standards,
28、and specifications for use in bioacoustics. 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
29、 S3 is as follows: Standards, specifications, 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/ASA S3.7-19
30、95 (R2008) American National Standard Method for Coupler Calibration of Earphones. That version of the standard, in addition to coupler calibration methods, contained detailed information about the audiometric ear, the 6 cm3coupler, and the 2 cm3coupler. Since that time, IEC 60318 was reorganized in
31、to several parts, which now include the same information about the aforementioned couplers (IEC 60318, Parts 1, 3, and 5, respectively). Given that the manufacture of these couplers has changed little if at all in more than 25 years, the fact that the IEC and ANSI/ASA specifications for these couple
32、rs are essentially identical, and the fact that manufacturers of these couplers do not produce different versions of the devices to meet alternative versions of the standards, harmonization was deemed appropriate. The first step in this process was the move of the detailed coupler specifications to
33、the nationally adopted international standard (NAIS) ANSI/ASA S3.55, Parts 1, 3, and 5, which correspond directly to their IEC 60318 counterparts. This revision of ANSI/ASA S3.7 focuses upon measurement methods for earphones, and now also points to the appropriate parts of NAIS ANSI/ASA S3.55 where
34、the detailed coupler information now resides. References in other standards that previously pointed to ANSI/ASA S3.7 for a particular coupler will now point to the appropriate NAIS ANSI/ASA S3.55 part instead, as these documents are revised and updated. Major changes in this document since the last
35、revision include: Revised title and scope. Updated references, including ANSI/ASA S3.55/IEC 60318, Parts 1, 3, and 5. Terms and definitions are updated. Reference is made to IEC 60268-7 for earphones for consumer applications. Clauses describing couplers and artificial ears are replaced with informa
36、tion about which coupler or ear simulator to use for a particular application, referencing the aforementioned documents. Only one measurement method is given. This is fully revised and updated. Measurements at constant available power are removed. All figures are updated and redrawn. Information abo
37、ut adaptors and configurations for insert earphones is updated and moved to an informative annex. This same information also appears in ANSI/ASA S3.22-2014. An informative annex has been added describing difference frequency and intermodulation distortion measurements. An informative annex has been
38、added regarding the uncertainty of measurement including an example uncertainty budget calculation for a typical earphone test. The Bibliography is revised with updated references. ANSI/ASA S3.7-2016 2016 Acoustical Society of America All Rights Reserved v At the time this Standard was submitted to
39、Accredited Standards Committee S3, Bioacoustics for approval, the membership was as follows: C.J. Struck, Chair P.B. Nelson, Vice-Chair S.B. Blaeser, Secretary Acoustical Society of America . C.J. Struck . P.B. Nelson (Alt.) American Academy of Audiology .C. Schweitzer . T. Ricketts (Alt.) American
40、Academy of Otolaryngology, Head and Neck Surgery, Inc. .R.A. Dobie A. Kim (Alt.) American Industrial Hygiene Association T.K. Madison D. Driscoll (Alt.) American Speech-Language-Hearing Association (ASHA) . L.A. Wilber . N. DiSarno (Alt.) Beltone/GN Resound . S. Petrovic Council for Accreditation in
41、 Occupational Hearing Conservation (CAOHC) . B. Charlton B. Kirchner (Alt.) Diagnostic Group T. McColley . P. Dobrowski (Alt.) ETS Lindgren Acoustic Systems . S. Dunlap D. Winker (Alt.) Etymotic Research, Inc. . M.C. Killion . J.K. Stewart (Alt.) Food and Drug Administration . S-C Peng . V. Dasika (
42、Alt.) G.R.A.S. Sound FAX: 631-923-2875; E-mail: asastdsacousticalsociety.org. ANSI/ASA S3.7-2016 2016 Acoustical Society of America All Rights Reserved vii Introduction This standard describes test methods and procedures for the measurement and calibration of earphones and receivers using couplers o
43、r ear simulators. Only the electroacoustic response is considered. Digital, wireless, and systems with signal processing are beyond the scope of this standard. Although there are no performance tolerances in this standard, the results of the tests in this standard may be used as the basis for establ
44、ishing performance tolerances. The earphone response, as perceived by the listener, is largely dependent upon the insertion gain of the system, i.e., the ratio of the pressure response as measured in-situ to the open-ear response in a given sound field (e.g., free field, diffuse field). This correct
45、ion to an equivalent sound field pressure is beyond the scope of this standard. Noise isolation afforded by earphones (analogous to hearing protectors) as well as measurements or limit recommendations for the maximum output of earphones in order to protect the hearing of the listener are also beyond
46、 the scope of this standard. Couplers used for earphone measurements are not designed to represent the real ear, but rather only to provide a convenient, stable, and reproducible acoustical load to enable a simple and ready means for the exchange of specifications and physical data. Often, as in pro
47、duction testing, exact correlation between the real-ear and coupler response is not required. Couplers are specified in ANSI/ASA S3.55-2014/Part 1/IEC 60318-1:2009, ANSI/ASA S3.55-2015/Part 3/IEC 60318-3:2014, and ANSI/ASA S3.55-2014/Part 5/IEC 60318-5:2006. Alternatively, ear simulators (as describ
48、ed in ANSI/ASA S3.25-2009) may be used to provide an acoustic impedance approximating the median adult human ear and equivalent sound pressure at the eardrum. The occluded ear simulator is used in test systems such as manikins. For telephony measurements, the ear simulators described in ITU-T Rec. P
49、.57 are used. ANSI/ASA S3.36-2012 describes a manikin (a.k.a. head and torso simulator) which is intended to simulate the acoustics of a median human adult, including diffractions affecting the in-situ performance of electroacoustic devices used on or near a person, where the effects of the pinna and realistic positioning of an earphone are also considered. AMERICAN NATIONAL STANDARD ANSI/ASA S3.7-2016 2016 Acoustical Society of America All Rights Reserved 1 American National Stan
