ISO INTERNATIONAL STANDARD 389-3 Second edition 2016-02-01 Acoustics Reference zero for the calibration of audiometric equipment - Part 3: Reference equivalent threshold vibratory force levels for pure tones and bone vibrators Acoustique - Zéro de reference pour I'étalonnage d'équipements audiométriques - Partie 3: Niveaux de réference équivalents de force vibratoire liminaire pour les vibrateurs a sons purs et les ossivibrateurs Reference number IS0 389-3:2016(E) ISO International Organization for Standardization @ IS0 2016 STANDARDIZATIONC15956617 ed without license from IHS IS0 389-3:2016(E) COPYRIGHT PROTECTED DOCUMENT Is0 2016, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form written permission. Permission can be requested from either Iso at the address below or Iso's member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 [email protected] www.iso.org Internatinir DrganizationforStandardization Licensee-ZHEJIANG INST OF STANDARDIZoISQ6 -All rights reserved Not for Resale, 2016/3/29 02:50:25 No reproduction or networking permited without license from IHS IS0 389-3:2016(E) Contents Page Foreword ..iv Introduction ..V 1 Scope. ..1 2 Normative references 3 Terms and definitions ..2 4 Reference equivalent threshold vibratory force levels (RETVFL) ..3 5 Test conditions and requirements 4 5.1 General. 4 5.2 Bonevibrator .4 5.3 Fitting of the bone vibrator .4 5.4 Mechanical coupler .5 5.5 Test signal. 5 5.6 Masking noise 5 5.7 Masking transducer 5 5.8 Fitting of masking transducer .5 5.9 Baseline masking level. ..6 Annex A (informative) Note on the derivation of RETVFL values. 7 Annex B (informative) Guidance on the application of the reference zero to the calibration ofbone-conductionaudiometers 8 Annex C (informative) Differences in reference equivalent threshold vibratory force levels between forehead and mastoid location of vibrator .10 Annex D (informative) Bone-conduction threshold of hearing for frequencies below 25o Hz. ..12 Bibliography .13 iii thout license from IHS