BS EN IEC 60118-9:2019
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Electroacoustics. Hearing aids – Methods of measurement of the performance characteristics of bone conduction hearing aids
| Published By | Publication Date | Number of Pages |
| BSI | 2019 | 34 |
IEC 60118-9:2019 specifies methods for the measurement of bone conduction hearing aid characteristics. The methods described will produce a suitable basis for the exchange of information or for direct comparison of the electroacoustical characteristics of bone conduction hearing aids. These methods are chosen to be practical and reproducible and are based on selected fixed parameters. The results obtained by the methods specified in this document express the performance under the conditions of measurement; however, the performance of the hearing aid under practical conditions of use will depend upon a number of factors (e.g. effective load impedance, environmental conditions, acoustical environment, etc.). This document defines methods of measurement of characteristics of bone conduction hearing aids both for â?¢ transcutaneously coupled devices measured on a mechanical coupler, meeting the requirements of IEC 60318-6, and â?¢ bone coupled/bone anchored devices measured on a skull simulator. IEC 60118-9:2019 cancels and replaces the first edition published in 1985. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) includes bone coupled devices measured on a skull simulator; b) measurement frequency range increased to 8 000 Hz for bone coupled devices.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 2 | undefined |
| 5 | Annex ZA(normative)Normative references to international publicationswith their corresponding European publications |
| 8 | English CONTENTS |
| 10 | FOREWORD |
| 12 | INTRODUCTION |
| 13 | 1 Scope 2 Normative references 3 Terms and definitions |
| 17 | 4 Measurement method 4.1 General 4.2 Mechanical coupler 4.3 Skull simulator 4.4 Measurement frequency range |
| 18 | 4.5 Reporting of data 5 Measurement enclosure and measurement equipment 5.1 General 5.2 Unwanted stimuli in the test enclosure 5.3 Sound source 5.4 Measurement system for the measurement of the vibratory force level produced by a bone conduction hearing aid |
| 19 | 5.5 Direct-current measuring system 5.6 Magnetic field source for ETLS and MMSL measurements |
| 20 | 6 Measurement conditions 6.1 General 6.2 Applying the bone vibrator to the mechanical coupler or skull simulator 6.2.1 Transcutaneously coupled devices 6.2.2 Bone coupled devices |
| 21 | 6.3 Control of the sound field Figures Figure 1 – Example of a bone coupled device(hearing aid with integral bone vibrator) mounted on a skull simulator |
| 22 | Figure 2 – Example of a transcutaneously coupled device (spectacle hearing aidwith an integral bone vibrator mounted in the spectacle arm)under measurement |
| 23 | Figure 3 – Example of a transcutaneously coupled device (hearing aid with externalbone vibrator) mounted on the mechanical coupler |
| 24 | 6.4 Ambient conditions 6.4.1 Measurement space 6.4.2 Bone vibrator, mechanical coupler and skull simulator Tables Table 1 – Resistors and open circuit voltages for zinc-air battery simulators |
| 25 | 7 Measurement procedures 7.1 Frequency response curves 7.2 OVFL90 frequency response curve |
| 26 | 7.3 Full-on acousto-mechanical sensitivity level frequency response Figure 4 – Example of OVFL90 curve and basic force level frequency response curve |
| 27 | 7.4 Basic vibratory force level frequency response 7.4.1 Measurement procedure 7.4.2 Frequency range 7.5 Total harmonic distortion |
| 28 | 7.6 Equivalent input noise 7.7 Battery current 7.8 Measurements for hearing aids having an induction pick-up coil 7.8.1 General Table 2 – Distortion test frequencies and input sound pressure levels |
| 29 | 7.8.2 Equivalent test loop sensitivity (ETLS) 7.8.3 Maximum HFA magneto-mechanical sensitivity level (HFA- MMSL) of induction pick-up coil 8 Maximum permitted expanded uncertainty of measurements |
| 30 | Figure 5 – Relationship between tolerance limits, corresponding acceptanceintervals and the maximum permitted uncertainty of measurement, UMAX |
| 31 | Table 3 – Example uncertainty budget |
| 32 | Bibliography |
