SIST EN ISO 11904-2:2005

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Akustik - Bestimmung der Schallimmission von ohrnahen Schallquellen - Teil 2: Verfahren unter Verwendung eines Kopf- und Rumpfsimulator (ISO 11904-2:2004)Acoustique - Détermination de l'exposition sonores due a des sources placées a proximité de l'oreille - Partie 2: Technique utilisant un mannequin (ISO 11904-2:2004)Acoustics - Determination of sound immission from sound sources placed close to the ear - Part 2: Technique using a manikin (ISO 11904-2:2004)33.160.50PriborAccessories17.140.01Acoustic measurements and noise abatement in generalICS:Ta slovenski standard je istoveten z:EN ISO 11904-2:2004SIST EN ISO 11904-2:2005en01-februar-2005SIST EN ISO 11904-2:2005SLOVENSKI
STANDARD



SIST EN ISO 11904-2:2005



EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN ISO 11904-2November 2004ICS 17.140.01English versionAcoustics - Determination of sound immission from soundsources placed close to the ear - Part 2: Technique using amanikin (ISO 11904-2:2004)Acoustique - Détermination de l'exposition sonores due àdes sources placées à proximité de l'oreille - Partie 2:Technique utilisant un mannequin (ISO 11904-2:2004)Akustik - Bestimmung der Schallimmission von ohrnahenSchallquellen - Teil 2: Verfahren unter Verwendung einesKopf- und Rumpfsimulators (ISO 11904-2:2004)This European Standard was approved by CEN on 14 October 2004.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2004 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 11904-2:2004: ESIST EN ISO 11904-2:2005



EN ISO 11904-2:2004 (E)
2
Foreword
This document (EN ISO 11904-2:2004) has been prepared by Technical Committee ISO/TC 43 "Acoustics" in collaboration with Technical Committee CEN/TC 211 "Acoustics", the secretariat of which is held by DS.
This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by May 2005, and conflicting national standards shall be withdrawn at the latest by May 2005.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Endorsement notice
The text of ISO 11904-2:2004 has been approved by CEN as EN ISO 11904-2:2004 without any modifications.
SIST EN ISO 11904-2:2005



Reference numberISO 11904-2:2004(E)© ISO 2004
INTERNATIONAL STANDARD ISO11904-2First edition2004-11-01Acoustics — Determination of sound immission from sound sources placed close to the ear — Part 2: Technique using a manikin Acoustique — Détermination de l'exposition sonore due à des sources placées à proximité de l'oreille —
Partie 2: Technique utilisant un mannequin
SIST EN ISO 11904-2:2005



ISO 11904-2:2004(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
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ii © ISO 2004 – All rights reserved
SIST EN ISO 11904-2:2005



ISO 11904-2:2004(E) © ISO 2004 – All rights reserved iii Contents Page Foreword.iv Introduction.v 1 Scope.1 2 Normative references.1 3 Terms and definitions.2 4 Measurement principle.3 5 Instrumentation.3 5.1 Manikin (head and torso simulator).3 5.2 Check of calibration.3 5.3 Filters.4 6 Determination of free-field or diffuse-field related equivalent continuous A-weighted sound pressure level.4 6.1 Measurement of manikin sound pressure level.4 6.2 Conversion to free-field or diffuse-field related sound pressure level.4 6.3 A-weighting and summation.6 7 Test report.6 Annex A (informative)
Example of sources of measurement uncertainty.7 Annex B (informative)
Example of an uncertainty analysis.14 Bibliography.16
SIST EN ISO 11904-2:2005



ISO 11904-2:2004(E) iv © ISO 2004 – All rights reserved Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 11904-2 was prepared by Technical Committee ISO/TC 43, Acoustics. ISO 11904 consists of the following parts, under the general title Acoustics — Determination of sound immission from sound sources placed close to the ear: =Part 1: Technique using a microphone in a real ear (MIRE technique) =Part 2: Technique using a manikin
SIST EN ISO 11904-2:2005



ISO 11904-2:2004(E) © ISO 2004 – All rights reserved v Introduction ISO 11904 is a series of standards which specify methods for the determination of sound immissions from sources located close to the ear in which situations the sound pressure level measured at the position of the exposed person (but with the person absent) does not adequately represent the sound exposure. In order to make it possible to assess the exposure by means of well-established criteria, the exposure of the ear is measured and subsequently converted into a corresponding free-field or diffuse-field level. The result is given as a free-field related or diffuse-field related equivalent continuous A-weighted sound pressure level, LFF,H,Aeq or LDF,H,Aeq when ISO 11904-1 is used, or LFF,M,Aeq or LDF,M,Aeq when ISO 11904-2 is used. ISO 11904-1 describes measurements carried out using miniature or probe microphones inserted in the ears of human subjects (microphones in real ear, MIRE technique). ISO 11904-2 describes measurements carried out using a manikin equipped with ear simulators including microphones (manikin technique). ISO 11904 may, for instance, be applied to equipment tests and the determination of noise exposure at the workplace where, in the case of exposure from sources close to the ears, the sound pressure level measured at the position of the exposed person (but with the person absent) does not adequately represent the sound exposure. Examples of applications are head- and earphones used to reproduce music or speech, whether at the workplace or during leisure, nailguns used close to the head, and combined exposure from a close-to-ear sound source and an external sound field. When specific types of equipment are to be tested (e.g. portable cassette players or hearing protectors provided with radio receivers), test signals suitable for this particular type of equipment have to be used. Neither such test signals nor the operating conditions of the equipment are included in ISO 11904 but might be specified in other standards. When workplace situations are measured, the various noise sources contributing to the immission should be identified. Operating conditions for machinery and equipment used might be specified in other standards. Both parts of ISO 11904 strive for the same result: a mean value for a population of the free-field or the diffuse-field related level. ISO 11904-1 does this by specifying the mean of measurements on a number of human subjects; ISO 11904-2 does this by using a manikin, which aims at reproducing the acoustical effects on an average human adult. However, the two methods yield different measurement uncertainties which can influence the choice of method. Only the method described in ISO 11904-1 gives results which indicate the variance in a human population. Information on the uncertainties is given in Annexes A and B. When using the MIRE technique for measurement of sound from earphones of insert and stethoscopic types, practical problems can occur with the positioning of microphones in the ear canal. When using the manikin technique, the head- or earphone has to be coupled to the pinna simulator and ear canal extension as far as possible in the way it is coupled to the human ear. In cases where head- or earphones or other objects touch the pinna, a possible deviation in stiffness or shape of the artificial pinna from human pinnae has a significant impact on the result and can even make the results invalid. An overview of the differences between the two parts of ISO 11904 is given in Table 0.1. SIST EN ISO 11904-2:2005



ISO 11904-2:2004(E) vi © ISO 2004 – All rights reserved Table 0.1 — Overview of differences between MIRE and manikin techniques Parameter ISO 11904-1 ISO 11904-2 Type of method Microphone in real ear technique Manikin technique Limitation of the method With earphones of insert and stethoscopic type, practical problems can occur with positioning of microphones in the ear canal. Proper coupling may not always be obtained if the artificial pinna deviates from human pinnae in stiffness or shape. In some cases the exposed person cannot be replaced by a manikin, e.g., if the person has to operate equipment. Main issues affecting accuracy Number of subjects When tabulated values are used for ∆LFF,H or ∆LDF,H: =calibration of ear canal microphone =accuracy in positioning of microphones in the ear canal When individual values are used for ∆LFF,H or ∆LDF,H: =quality of reference sound field =stability of sensitivity and frequency response as well as position of ear canal microphone
Similarity of manikin to humans Calibration of manikin Frequency range 20 Hz to 16 kHz 20 Hz to 10 kHz
SIST EN ISO 11904-2:2005



INTERNATIONAL STANDARD ISO 11904-2:2004(E) © ISO 2004 – All rights reserved 1 Acoustics — Determination of sound immission from sound sources placed close to the ear — Part 2: Technique using a manikin 1 Scope This part of ISO 11904 specifies basic framework measurement methods for sound immission from sound sources placed close to the ear. These measurements are carried out with a manikin, equipped with ear simulators including microphones. The measured values are subsequently converted into corresponding free-field or diffuse-field levels. The results are given as free-field related or diffuse-field related equivalent continuous A-weighted sound pressure levels. The technique is denoted the manikin technique. This part of ISO 11904 is applicable to exposure to sound from sources close to the ear, for example during equipment tests or at the workplace to sound from earphones or hearing protectors with audiocommunication facilities. This part of ISO 11904 is applicable in the frequency range from 20 Hz to 10 kHz. For frequencies above 10 kHz, ISO 11904-1 can be used. 2 Normative references 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 of the referenced document (including any amendments) applies. IEC 60942:2003, Electroacoustics — Sound calibrators IEC 61260:1995, Electroacoustics — Octave-band and fractional-octave-band filters IEC 61672-1, Electroacoustics — Sound level meters — Part 1: Specifications ITU-T P.58:1996, Head and torso simulator for telephonometry GUM:19931), Guide to the expression of uncertainty in measurement. BIPM, IEC, IFCC, ISO, IUPAC, IUPAP, OIML, 1995
1) Corrected and reprinted in 1995. SIST EN ISO 11904-2:2005



ISO 11904-2:2004(E) 2 © ISO 2004 – All rights reserved 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 manikin sound pressure level LM,exp,f equivalent continuous sound pressure level in one-third-octave frequency bands with nominal midband frequency f, measured with the microphone of an ear simulator integrated in a manikin when the manikin is exposed to the sound under test 3.2 free-field frequency response for use with manikins ∆LFF,M,f average human free-field frequency response for use with manikins, corrected for the difference between the sound transmission inside the average human ear canal and the corresponding transmission of the manikin ear simulator NOTE 1 For applicability with manikins, the eardrum reference is replaced by the output of the manikin ear simulator in tabulated values of ∆LFF,M,f. NOTE 2 The free-field frequency response for use with manikins is identical to the amplitude of the head-related transfer function (HRTF) for frontal sound incidence. NOTE 3 The human free-field frequency response is defined in ISO 11904-1. 3.3 diffuse-field frequency response for use with manikins ∆LDF,M,f average human diffuse-field frequency response for use with manikins, corrected for the difference between the sound transmission inside the average human ear canal and the corresponding transmission of the manikin ear simulator NOTE 1 For applicability with manikins, the eardrum reference is replaced by the output of the manikin ear simulator in tablulated values of ∆LDF,M,f. NOTE 2 The human diffuse-field frequency response is defined in ISO 11904-1. 3.4 free-field related sound pressure level determined with a manikin LFF,M free-field sound pressure level determined with the method of this part of ISO 11904 NOTE 1 The definition may be applied to specific frequencies or frequency bands, weighted or unweighted levels, specific time weightings, etc., for instance “free-field related equivalent continuous A-weighted sound pressure level" (free-field related LM,Aeq, also denoted LFF,M,Aeq). NOTE 2 The method is aimed at the mean free-field related sound pressure level that would be obtained with a large human population. NOTE 3 The free-field related sound pressure level for a human subject is defined in ISO 11904-1. 3.5 diffuse-field related sound pressure level determined with a manikin LDF,M diffuse-field sound pressure level determined with the method of this part of ISO 11904 SIST EN ISO 11904-2:2005



ISO 11904-2:2004(E) © ISO 2004 – All rights reserved 3 NOTE 1 The definition may be applied to specific frequencies or frequency bands, weighted or unweighted levels, specific time weightings, etc., for instance “diffuse-field related equivalent continuous A-weighted sound pressure level" (diffuse-field related LM,Aeq, also denoted LDF,M,Aeq). NOTE 2 The method is aimed at the mean diffuse-field related sound pressure level that would be obtained with a large human population. NOTE 3 The diffuse-field related sound pressure level for a human subject is defined in ISO 11904-1. 4 Measurement principle A manikin (head and torso simulator) is exposed to the sound source(s) in question and, for each of the ear simulators integrated in the manikin, the sound pressure level is measured in one-third-octave frequency bands, LM,exp,f. Each of the one-third-octave-band levels is adjusted with th
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