ISO INTERNATIONAL STANDARD 11904-1 First edition 2002-10-01 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) Acoustique - Détermination de I'exposition sonore due a des sources sonores placées a proximité de I'oreille- Partie 1: Technique du microphone placé dans une oreille reelle (technique MIRE) Reference number ISO 11904-1:2002(E) ISo @ ISO 2002 HS unde Not for Resale ISO 11904-1:2002(E) PDFdisclaimer 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 @ISO2002 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic in the country of the requester. ISO copyright office Case postale 56. CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.ch Printed in Switzerland @ISO2002-All rights reserved py IHS unde ermittedwithoutlicense from IHS Not for Resale ISO 11904-1:2002(E) Contents Page Foreword iv Introduction 1 Scope 2 Normative references... 3 Terms and definitions. 4 Measurement principle.. 5 Instrumentation . 5.1 Ear canal microphone.. 5.2 Reference field microphone.. 5.3 Check of calibration .... 5.4 Filters. 6 Subjects 7 Useofearcanalmicrophone. 7.1 Choice of ear canal measurement position... 7.2 Mounting of microphones..... 6 7.3 6 8 Determinationoffree-fieldordiffuse-field related equivalentcontinuousA-weighted sound pressure level..... 8.1 Measurement of ear canal sound pressure level... 8.2 Conversion to free-field or diffuse-field related sound pressure level..... 8.3 A-weighting and summation...... 9 Free-field and diffuse-field frequency responses for selected ear canal measurement positions .... 7 10 Determination of free-field or diffuse-field frequency responses... 10.1 General...... 10.2 Measurement principle..... 10.3 Establishmentofafreereferencesoundfield 10.4 Establishment of a quasi-free reference sound field ... 10.5 Establishment of a diffuse reference sound field .... 10.6 Measurement of the reference sound field.... 10.7 Measurement of ear canal sound pressure level in reference sound field... 10.8 Determination of free-field or diffuse-field frequency response ... 10 10.9 Simplifications in specific cases. 10.10 Optional check of the measurement arrangement... 10 11 Test report.... 10 Annex A (informative) Example of sources of measurement uncertainty 11 Annex B (informative) Example of an uncertainty analysis 17 Bibliography.... 19 ii d by IHS under lice Not for Resale ISO 11904-1:2002(E) Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies (isO committees. Each member body interested in a subject for which a technical committee has been established has 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/lEC Directives, Part 3. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are ci