1、BS EN 50332-3:2017Sound system equipment:headphones and earphonesassociated with personal musicplayers maximum soundpressure level measurementmethodologyPart 3: measurement method for sounddose managementBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS EN 50332-3:2
2、017 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 50332-3:2017. The UK participation in its preparation was entrusted to TechnicalCommittee EPL/108, Safety of electronic equipment within thefield of audio/video, information technology and communicationtechnolo
3、gy.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2017. Published by BSI Stand
4、ards Limited 2017ISBN 978 0 580 95273 9ICS 17.140.50; 33.160.50Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 28 February 2017.Amendments/Corrigenda issued since
5、publicationDate Text affectedBS EN 50332-3:2017EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 50332-3 February 2017 ICS 17.140.50; 33.160.50 English Version Sound system equipment: headphones and earphones associated with personal music players - maximum sound pressure level measurement method
6、ology - Part 3: measurement method for sound dose management quipements de diffusion sonore: casques et couteurs associs avec un lecteur de musique individuel - Mthode de mesure de niveau maximal de pression acoustique - Partie 3: Mthode de mesure pour la gestion de la dose de bruit Elektroakustisch
7、e Gerte: Kopfhrer und Ohrhrer in Verbindung mit tragbaren Audiogerten - Verfahren zur Messung des maximalen Schalldruckpegels - Teil 3: Messmethode fr Schalldosis Management This European Standard was approved by CENELEC on 2017-01-02. CENELEC members are bound to comply with the CEN/CENELEC Interna
8、l 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 concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CE
9、NELEC 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 into its own language and notified to the CEN-CENELEC Management Centre has the same status as the offici
10、al versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Ma
11、lta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN
12、-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members. Ref. No. EN 50332-3:2017 E BS EN 50332-3:2017EN 50332-3:2017 (E) 2 Contents PageEuropean foreword .3 Introduction .4 1 Scope .5 2
13、 Normative references .5 3 Terms and definitions 5 4 Limits and calibration 5 4.1 General 5 4.2 Headset Type variations 6 4.3 Headset Fit-variation 6 5 Testing .6 5.1 General 6 5.2 Test of PMP with headphones/plugs included 6 5.3 Test of PMP with headphones/plugs not included .7 Annex A (Informative
14、) Example of how the basic protections could be achieved 9 Annex B (Informative) Background information . 10 B.1 Motivation 10 B.2 Loudness Normalization and EBU R128 . 11 B.3 Explanation of MEL . 11 B.4 Explanation of CSD . 11 B.5 Sound of non-PMP origin . 12 Bibliography . 13 BS EN 50332-3:2017EN
15、50332-3:2017 (E) 3 European foreword This document (EN 50332-3:2017) has been prepared by CLC/TC/108X “Safety of electronic equipment within the fields of Audio/Video, Information Technology and Communication Technology”. The following dates are fixed: latest date by which this document has tobe imp
16、lemented at national level bypublication of an identical national standardor by endorsement(dop) 2018-01-02 latest date by which the national standardsconflicting with this document have tobe withdrawn(dow) 2020-01-02 Attention is drawn to the possibility that some of the elements of this document m
17、ay be the subject of patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights. This document has been prepared under a mandate given to CENELEC by the European Commission and the European Free Trade Association. BS EN 50332-3:2017EN 50332-3:2017 (E) 4 Introd
18、uction Ideally, sound exposure assessment should be done with a normalized dosimeter located close to the head (ears) of the user during the whole time of the exposure. However, in the context of leisure activities, and for evident practical and economical reasons, this ideal methodology cannot be a
19、pplied. For a user of a Personal Music Player (PMP), a dosimeter would even have to sit inside the ear canal, close to the tympanic membrane, with exposure data transformed to diffuse field equivalent. The aim of this European Standard is to define an alternative and more applicable methodology for
20、estimating sound exposure from PMPs. A PMP should inform the user about potentially harmful sound exposure, long-term as well as short-term. This is accomplished by including a rolling calculation of sound dose, CSD, and an estimation of momentary sound exposure level, MEL. In case CSD or MEL exceed
21、s defined thresholds, the user is warned and/or PMP gain is lowered. All protections should remain in place when listening to any kind of typical PMP source (music, broadcast, game etc.), but not when, for instance, having a phone call. Annex A shows a block diagram of how a complete protection syst
22、em might be realized. By adding actual PMP dose estimation to EN 50332-1 and EN 50332-2, rather than assuming the average energy of programs and tracks, warnings become more relevant to the user. Relevance and trustworthiness is essential for one of the standards objectives: its educational value. I
23、f estimation relies only on feed-forward principles, some uncertainty in the prediction of in vivo dose will persist, for instance how earplugs or headphones are mounted, spread between transducers, spectral properties of transducers, broken transducers etc. Some uncertainties can be effectively dea
24、lt with when known combinations of PMPs and headphones are employed, while it may add to the uncertainty when components are acquired separately. Regardless that earphones, earbuds or headphones for use with PMPs may not exceed defined limits with regard to sensitivity, it is acknowledged that extra
25、 uncertainty in the exposure estimation with arbitrary combinations of PMPs and transducers will persist. However, with this part 3, actual electrical measurement of source audio as part of dose estimation, a major contributor to warning errors in general, is eliminated. BS EN 50332-3:2017EN 50332-3
26、:2017 (E) 5 1 Scope This European Standard specifies sound dose measurement, and the alerts associated, to reduce the risk of listeners developing hearing impairment when using a Personal Music Player (PMP). The standard does not cover exposure from other sources than PMPs. 2 Normative references Th
27、e following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 50332-
28、1:2013, Sound system equipment: Headphones and earphones associated with personal music players - Maximum sound pressure level measurement methodology - Part 1: General method for “one package equipment“ EN 50332-2:2013, Sound system equipment: Headphones and earphones associated with personal music
29、 players - Maximum sound pressure level measurement methodology - Part 2: Matching of sets with headphones if either or both are offered separately, or are offered as one package equipment but with standardised connectors between the two allowing to combine components of different manufacturers or d
30、ifferent design EN 62368-1, Audio/video, information and communication technology equipment - Part 1: Safety requirements (IEC 62368-1:2014) HD 483.1 S2, Sound system equipment - Part 1: General 3 Terms and definitions For the purposes of this document, the terms and definitions of EN 50332-1:2013,
31、EN 50332-2:2013 and EN 62368-1 apply. 4 Limits and calibration 4.1 General EN 50332-3 builds on definitions from EN 50332-1 and EN 50332-2. Output limits and the calibration of the electro-acoustic loop remain unchanged, but actual audio shall be taken into account to determine maximum and minimum g
32、ain settings. With the test signal, the relationship between sound exposure level and r.m.s. voltage remains the same, e.g. 80 dB SPL and 15 mV (EN 50332-2), see Figure 1. BS EN 50332-3:2017EN 50332-3:2017 (E) 6 Figure 1 Relationship between SPL and analog output voltage (mV r.m.s.), CSD reference a
33、nd MEL-based warning; for the standard test signal 4.2 Headset Type variations If a manufacturer implements a means of detecting the sensitivity of a headset plugged in, or provides a user selectable option, this sensitivity can be used to re-calibrate the electro-acoustic loop used for the limits a
34、nd dose calculation, as long as the acoustic limits remain unchanged. 4.3 Headset Fit-variation If a manufacturer implements a system accounting for headset fit-variation, in which the acoustic level estimates are more accurate than the proposed feed-forward system (for example, a closed-loop or hyb
35、rid system), these levels can serve as the limits and inputs to the dose calculation, as long as the acoustic limits remain unchanged. 5 Testing 5.1 General This procedure verifies PMP sound exposure and dose estimation, based on the HATS method for acoustic testing, see EN 50332-1. (Five times re-s
36、eat calibration ref). The “programme simulation” test signal specified in EN 50332-1 and EN 503322 is here referred to as “HD 483”. The same signal, but attenuated by 12 dB, is referred to as “HD 483-12L”. Additional signals and more extensive procedures could be included to test the warning system
37、rigorously; for example, mark-space ratio noise, test music etc. To keep it simple, however, requirements are based only on continuous noise as described in EN 503321 and 2, as the intentions behind dose estimation should be clear. 5.2 Test of PMP with headphones/plugs included 1) Exposure-based war
38、ning: Use measurement procedure of EN 50332-1. Play the HD 483 signaland adjust PMP gain control until the MEL warning is just activated. Measure the manikin diffusefield equivalent sound exposure and verify performance to be within tolerances, +- 3 dB.In case PMP maximum SPL is less than 99 dB, no
39、Exposure-based warning is required.BS EN 50332-3:2017EN 50332-3:2017 (E) 7 2a) Dose estimation: Reset the CSD measurement and adjust the gain for a close to 100 dB SPL diffuse field equivalent measurement. Based on Table 1 and on the SPL measured, verify the time it takes for CSD to reach 100 %. Dur
40、ation tolerance: +/- 3 dB time equivalents (Table 1). Verify that an appropriate CSD warning is given. 2b) Continue playing and verify that SPL is reduced to 80 dB SPL +/- 3 dB when a CSD of 500 % is reached. Duration tolerance: +/- 3 dB time equivalents (Table 1). In case PMP maximum SPL is less th
41、an 80 dB, no Dose estimation is required. In case PMP max SPL is between 80 dB and 100 dB, set max PMP gain and use interpolation to verify dose estimates. 3) EBU R128 compatibility (optional): Switch source to HD 483-12L and verify that gain can beturned up high enough to produce SPL greater than o
42、r equal to 90 dB.5.3 Test of PMP with headphones/plugs not included 1) Exposure warning: Play the HD 483 test signal and adjust PMP gain control until the MEL warningis just activated. Measure the output r.m.s. voltage and verify performance within tolerances,133 mV - 169 mV = +/- 1dB.In case PMP ma
43、ximum output is less than 133 mV, no Exposure-based warning is required.2a) Dose estimation: Reset the CSD measurement and adjust the gain for a close to 150 mV r.m.s. per channel reading. Based on Table 1 and on the voltage measured, verify the time it takes for CSD to reach 100 %. Duration toleran
44、ce: +/- 1 dB time equivalents (Table 1). Verify that an appropriate CSD warning is given. 2b) Continue playing and verify that output voltage is reduced to 15 mV +/- 1 dB when a CSD of 500 % is reached. Duration tolerance: +/- 1 dB time equivalents (Table 1). In case the PMPs maximum output voltage
45、less than or equal to 15 mV, no dose estimation is required. In case the PMPs maximum output voltage is between 15 mV and 150 mV, set max PMP gain and use interpolation to verify dose estimates. 3) EBU R128 compatibility (optional): Switch source to HD 483-12L and verify that the gain can beturned u
46、p high enough to generate an output voltage of greated than or equal to 47 mV.BS EN 50332-3:2017EN 50332-3:2017 (E) 8 Table 1 Testing of CSD alert, based on SPL or on Electrical Level SPL Analog Level r.m.s. Duration for 100 %CSD Duration for 500 %CSD 103,0 dB(A) 211,9 mV 12 min 59,5 min 102,5 dB(A)
47、 200,0 mV 13,5 min 67 min 102,0 dB(A) 188,8 mV 15 min 75 min 101,5 dB(A) 178,3 mV 17 min 84 min 101,0 dB(A) 168,3 mV 19 min 94,5 min 100,5 dB(A) 158,9 mV 21 min 106 min 100,0 dB(A) 150,0 mV 23,5 min 119 min 99,5 dB(A) 141,6 mV 26,5 min 133,5 min 99,0 dB(A) 133,7 mV 30 min 150 min 98,5 dB(A) 126,2 mV
48、 33,5 min 168,5 min 98,0 dB(A) 119,1 mV 37,5 min 189 min 97,5 dB(A) 112,5 mV 42 min 212 min 97,0 dB(A) 106,2 mV 47,5 min 238 min 96,5 dB(A) 100,3 mV 53 min 267,5 min 96,0 dB(A) 94,6 mV 59,5 min 300 min 95,5 dB(A) 89,3 mV 67 min 337 min 95,0 dB(A) 84,4 mV 75 min 378 min 94,5 dB(A) 79,6 mV 84 min 424
49、min 94,0 dB(A) 75,2 mV 94,5 min 476,5 min 93,5 dB(A) 71,0 mV 106 min 534,5 min 93,0 dB(A) 67,0 mV 119 min 600 min 92,5 dB(A) 63,3 mV 133 min 673,5 min 92,0 dB(A) 59,7 mV 150 min 756 min When testing CSD, this table may be used in case the PMPs gain control does not allow hitting an SPL or voltage level precisely enough. (Duration rounded to 1/2 min values). BS EN 50332-3:2017EN 50332-3:2017 (E) 9 Annex A (Informative) Example of how the basic protections could be achieved To reduce measurement uncertainty, electro-acoustical (“E-A”) tuning should be invoke
