1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 60268-16:2011Sound system equipment Part 16: Objective rating of speech intelligibility by speech transmission indexBS EN 60268-16:2011 BRITISH STANDARDNational forewordThi
2、s British Standard is the UK implementation of EN 60268-16:2011. It is identical to IEC 60268-16:2011. It supersedes BS EN 60268-16:2003 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee EPL/100, Audio, video and multimedia systems and equipment.A list o
3、f organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. BSI 2011 ISBN 978 0 580 76163 8 ICS 33.160.01 Compliance with a Britis
4、h Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 September 2011.Amendments issued since publicationDate T e x t a f f e c t e dBS EN 60268-16:2011EUROPEAN STANDARD EN 60268-16 NORME E
5、UROPENNE EUROPISCHE NORM August 2011 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2011 CENELEC - All rights of exploitation in an
6、y form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60268-16:2011 E ICS 33.160.01 Supersedes EN 60268-16:2003English version Sound system equipment - Part 16: Objective rating of speech intelligibility by speech transmission index (IEC 60268-16:2011) Equipements pour systmes
7、lectroacoustiques - Partie 16: Evaluation objective de lintelligibilit de la parole au moyen de lindice de transmission de la parole (CEI 60268-16:2011) Elektroakustische Gerte - Teil 16: Objektive Bewertung der Sprachverstndlichkeit durch den Sprachbertragungsindex (IEC 60268-16:2011) This European
8、 Standard was approved by CENELEC on 2011-08-02. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references co
9、ncerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member in
10、to its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Icel
11、and, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 60268-16:2011EN 60268-16:2011 - 2 - Foreword The text of document 100/1812/FDIS, future edition 4 of IEC 60268-1
12、6, prepared by IEC TC 100, Audio, video and multimedia systems and equipment, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60268-16 on 2011-08-02. This European Standard supersedes EN 60268-16:2003. EN 60268-16:2011 includes the following technical changes with re
13、spect to EN 60268-16:2003: development of more comprehensive, complete and unambiguous standardization of the STI methodology; the term STIris discontinued. A new function for the prediction of auditory masking effects is introduced; the concept of speech level and the setting of the level of the te
14、st signal have been introduced; additional information has been included on prediction and measurement procedures. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and CENELEC shall not be held responsible for identifying any o
15、r all such patent rights. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2012-05-02 latest date by which the national standards conflicting with the EN have to be withdrawn (
16、dow) 2014-08-02 Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 60268-16:2011 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes have to be added for the standards
17、 indicated: 2 IEC 60318-1:2009 NOTE Harmonized as EN 60318-1:2009 (not modified). 3 IEC 61672 series NOTE Harmonized in EN 61672 series. 37 ISO 7029:2000 NOTE Harmonized as EN ISO 7029:2000. 44 ISO 3382-1:2009 NOTE Harmonized as EN ISO 3382-1:2009. _ BS EN 60268-16:2011- 3 - EN 60268-16:2011 Annex Z
18、A (normative) Normative references to international publications with their corresponding European publications The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition
19、of the referenced document (including any amendments) applies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 61260 + A1 1995 2001 Electroacoustics - Octave-band and fractional-oc
20、tave-band filters EN 61260 + A1 1995 2001 ISO 18233 2006 Acoustics - Application of new measurement methods in building and room acoustics EN ISO 18233 2006 2 60268-16 IEC:2011(E) CONTENTS FOREWORD . 5 INTRODUCTION . 7 1 Scope . 9 2 Normative references . 9 3 Terms and definitions . 9 4 Description
21、of the STI method 15 4.1 General . 15 4.1.1 Rationale for the STI method . 15 4.1.2 Applicability of the STI method 15 4.2 Background of the STI method 16 4.2.1 General . 16 4.2.2 Theoretical overview 17 4.2.3 Measurement of STI 18 4.3 Applicability of STI test methods . 19 4.4 Use of direct and ind
22、irect methods 20 4.5 Limitations of the STI method 21 4.5.1 General . 21 4.5.2 Frequency shifts 21 4.5.3 Centre clipping 22 4.5.4 Drop outs 22 4.5.5 Jitter 22 4.5.6 Vocoders . 22 4.5.7 Overestimation of STI under low background noise conditions . 22 4.5.8 Frequency response 22 4.5.9 Echoes 23 4.5.10
23、 Fast amplitude compression and expansion . 23 4.5.11 Non-linear distortion 24 4.5.12 Impulsive and fluctuating noise 24 4.5.13 Hearing impaired listeners . 24 4.6 Conclusion 24 5 Direct method of measuring STI . 24 5.1 Overview . 24 5.2 STIPA . 25 5.3 Application 26 5.4 Limitations . 26 6 Indirect
24、method of measuring STI using the impulse response 26 6.1 Overview . 26 6.2 Application 27 6.3 Limitations (non-linear distortion) 28 7 Measurement procedures, post-processing of data and applications . 28 7.1 General . 28 7.2 Acoustical input . 28 7.3 Acoustical output . 30 7.4 Electrical input 30
25、7.5 Electrical output 30 7.6 Examples of input/output combinations 30 60268-16 IEC:2011(E) 3 7.6.1 Acoustical input Acoustical output 30 7.6.2 Electrical input Electrical output (e.g. assessment of wired and wireless) communication systems) . 30 7.6.3 Acoustical input Electrical output (e.g. assessm
26、ent of microphones) . 31 7.6.4 Electrical input Acoustical output (e.g. assessment of PA systems) 31 7.7 Post-processing of measured MTF data 31 7.8 Issues concerning noise 31 7.8.1 General . 31 7.8.2 Measurement of background noise 32 7.8.3 Fluctuating noise . 32 7.9 Analysis and interpretation of
27、the results . 32 7.10 Binaural STI measurements 33 8 Use of STI as a design prediction tool 33 8.1 Overview . 33 8.2 Statistical predictions 33 8.3 Prediction from simulated impulse response 34 Annex A (normative) Speech transmission index (STI) and revised STI methods . 35 Annex B (normative) STIPA
28、 method . 47 Annex C (normative) STITEL method . 48 Annex D (informative) RASTI method (obsolete) 49 Annex E (informative) Qualification of the STI and relationships with other speech intelligibility measures. 51 Annex F (informative) Nominal qualification bands for STI . 53 Annex G (informative) Ex
29、amples of STI qualification bands and typical applications . 54 Annex H (informative) Non-native listeners 55 Annex I (informative) Effect of age-related hearing loss and hearing impairment on speech intelligibility. 56 Annex J (normative) Calibration of STI test signal level . 57 Annex K (informati
30、ve) Example test report sheet for STI measurements 59 Annex L (normative) Prediction of STI using statistical methods 61 Annex M (informative) Adjustments to measured STI and STIPA results for simulation of occupancy noise and different speech levels 63 Annex N (informative) Other methods of determi
31、ning speech intelligibility 67 Bibliography 69 Figure 1 Concept of the reduction in modulation due to a transmission channel . 16 Figure 2 Modulation transfer function Input/output comparison 17 Figure A.1 Envelope function (panel A) of a 10 s speech signal for the 250 Hz octave band and correspondi
32、ng envelope spectrum (panel B) . 35 Figure A.2 Theoretical expression of the MTF 36 Figure A.3 Measurement system and frequencies for the STI method 38 Figure A.4 Auditory masking of octave band (k 1) on octave band (k) . 39 Figure D.1 Illustration of a practical RASTI test signal . 50 Figure E.1 Re
33、lationships between some speech intelligibility measures 51 Figure E.2 Relationship between STI, speech intelligibility scores and listening difficulty ratings 34, 35 52 Figure F.1 STI qualification bands 53 4 60268-16 IEC:2011(E) Table 1 Comparison of STI test methods for different types of distort
34、ion 19 Table 2 Applicability of test 20 Table 3 Choice of method 21 Table A.1 Auditory masking as a function of the octave band level. 40 Table A.2 Absolute speech reception threshold level in octave bands 41 Table A.3 MTI octave band weighting factors . 41 Table A.4 Octave band levels (dB) relative
35、 to the A-weighted speech level 42 Table B.1 Modulation frequencies for the STIPA method 47 Table C.1 Modulation frequencies for the STITEL method 48 Table D.1 Modulation frequencies for the RASTI method . 49 Table E.1 Categories for listening difficulty 52 Table G.1 Examples between STI qualificati
36、on bands and typical applications . 54 Table H.1 Adjusted intelligibility qualification tables for non-native listeners . 55 Table I.1 Adjusted intelligibility qualification tables for normal listeners and people over 60 years old with hearing loss . 56 Table M.1 Example calculation 63 60268-16 IEC:
37、2011(E) 5 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ SOUND SYSTEM EQUIPMENT Part 16: Objective rating of speech intelligibility by speech transmission index FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electr
38、otechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifica
39、tions, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. Internationa
40、l, governmental and non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal dec
41、isions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees. 3) IEC Publications have the form of recommendations for inte
42、rnational use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user. 4) In o
43、rder to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be c
44、learly indicated in the latter. 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certificatio
45、n bodies. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, pr
46、operty damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications. 8) Attention is drawn to the Normative references cited i
47、n this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying a
48、ny or all such patent rights. International Standard IEC 60268-16 has been prepared by IEC technical committee 100: Multimedia equipment and systems. This fourth edition cancels and replaces the third edition, published in 2003, and constitutes a technical revision. This edition includes the followi
49、ng significant technical changes with respect to the previous edition: development of more comprehensive, complete and unambiguous standardization of the STI methodology; the term STIris discontinued. A new function for the prediction of auditory masking effects is introduced; the concept of speech level and the setting of the level of the test signal have been introduced; 6 60268-16 IEC:2011(E) additional informa
