BSI PD IEC/TS 62886:2016
$189.07
Electroacoustics. Hearing aids. Method for measuring electroacoustic performance up to 16 kHz
| Published By | Publication Date | Number of Pages |
| BSI | 2016 | 46 |
IEC TS 62886:2016(E) which is a Technical Specification, describes a coupler and measurement methods to characterise the electroacoustic performance of hearing aids and insert earphones primarily in the range of 8 kHz to 16 kHz.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 4 | CONTENTS |
| 7 | FOREWORD |
| 9 | INTRODUCTION |
| 10 | 1 Scope 2 Normative references 3 Terms, definitions and abbreviated terms 3.1 Terms and definitions |
| 11 | 3.2 Abbreviated terms 4 Mechanical design of the 0,4 cm3 coupler 4.1 General |
| 12 | 4.2 Cavity dimensions 4.2.1 Critical dimensions 4.2.2 Effective coupler volume Figures Figure 1 – Mechanical design of the 0,4 cm3 coupler, shown with removable coupling plate with a nipple for the attachment of coupling tubing |
| 13 | 4.2.3 Diameter of the coupler cavity 4.3 Verification procedure of the effective coupler volume 4.3.1 General 4.3.2 Test set-up 4.3.3 Effective volume of the coupler under test |
| 14 | 4.4 Measuring microphone 4.4.1 General 4.4.2 Preferred microphone 4.4.3 Alternative microphones 4.5 Static pressure equalisation vent 5 Calibration 5.1 Reference environmental conditions |
| 15 | 5.2 Calibration procedure 6 Coupling of receivers and hearing aids to the coupler 6.1 Coupling to a hearing aid receiver by means of tubing 6.2 Coupling to a hearing aid embedded in or connected to an earmould Figure 2 – Coupling to a hearing aid receiver by means of coupling tubing |
| 16 | 6.3 Coupling to a receiver in the canal (RIC hearing aid) Figure 3 – Coupling to an ITE hearing aid |
| 17 | 6.4 Coupling to a BTE hearing aid with 2 mm continuous internal diameter tubing Figure 4 – Coupling to a receiver in the canal (RIC hearing aid) |
| 18 | 6.5 Coupling to a BTE hearing aid with earmould simulator Figure 5 – Coupling to a BTE hearing aid with 2 mm continuous internal diameter tubing |
| 19 | 6.6 Coupling to a BTE hearing aid with thin tubing Figure 6 – Coupling to a BTE hearing aid with earmould simulator |
| 20 | 7 Transfer impedance of the 0,4 cm3 coupler Figure 7 – Coupling to a BTE hearing aid with thin coupling tubing |
| 21 | 8 Comparison of the 0,4 cm3, the 2 cm3 coupler and the occluded-ear simulator 8.1 Sound pressure level frequency response curves Figure 8 – Magnitude frequency response of the transfer impedance frequency and the related equivalent volume |
| 22 | 8.2 Comparison of the coupler impedance with typical source impedances Figure 9 – Comparative measurement of the 0,4 cm3 coupler, the 2 cm3 coupler and the occluded-ear simulator frequency responses |
| 23 | 8.3 Influence of sound source impedance on measured level difference between the 0,4 cm3 coupler and the 2 cm3 coupler Figure 10 – Magnitude frequency responses of acoustic impedance of the 2 cm3, the 0,4 cm3 coupler and various hearing aid types |
| 24 | 9 Maximum permitted expanded uncertainty for coupler conformance testing Figure 11 – Deviation from the normalized coupler volume ratio as a function of the effective volume of the sound source Vs |
| 25 | 10 Measurements using the 0,4 cm3 coupler 10.1 General 10.2 Test enclosure and test equipment 10.3 Extended frequency range for total harmonic distortion measurements Tables Table 1 – Values of Umax for basic measurements |
| 26 | 10.4 Presentation of data 10.4.1 General 10.4.2 Presentation as 0,4 cm3 coupler data 10.4.3 Presentation as normalised to 2 cm3 coupler data 10.5 Maximum permitted expanded uncertainty of measurements performed using the 0,4 cm3 coupler Table 2 – Distortion test frequencies and input sound pressure levels |
| 27 | Table 3 – Values of Umax for basic measurements |
| 28 | Annex A (informative) Response transforms between the 0,4 cm3 coupler and the occluded-ear simulator A.1 General A.2 Simulation model of the human ear and approximation of λ/2 resonances |
| 29 | Figure A.1 – Electrical analogue model of the human ear |
| 30 | A.3 Measured and simulated transform responses of a standard-fitting Figure A.2 – Measured transform response of a standard-fitting |
| 31 | A.4 Transform curves for CIC-fitting and deep-insertion-fitting Figure A.3 – Comparison between the measured and the simulated standard-fitting transform response |
| 32 | Figure A.4 – Transform responses for (a) standard-fitting, b) CIC-fittingand (c) deep-insertion-fitting |
| 33 | Table A.1 – Transform data for standard-fitting (fitting at reference plane), CIC-fitting and deep-insertion-fitting |
| 35 | Annex B (informative) Measurement and modelling of the transfer impedance of the 0,4 cm3 coupler B.1 Measurement procedure B.1.1 Transfer impedance B.1.2 Calibration of the volume velocity source at 250 Hz |
| 36 | B.1.3 Calibration of the volume velocity source over the frequency range from 100 Hz to 60 kHz B.1.4 Test set-up for measuring the coupler transfer impedance |
| 37 | B.2 Measurement of the coupler transfer impedance Figure B.1 – Test set-up for measuring the coupler transfer impedance Figure B.2 – Average frequency response of 8 coupler measurements |
| 38 | Figure B.3 – Average transfer impedance of the 0,4 cm3 coupler Figure B.4 – Transfer impedance times frequency re 1 Pa/m3 in dB and as equivalent volume in mm3 in the frequency range 100 Hz to 60 kHz |
| 39 | Table B.1 – Transfer impedance of the 0,4 cm3 coupler in the frequency range from 100 Hz to 60 kHz |
| 40 | B.3 Electrical analogue representation of the coupler as a tube model |
| 41 | Figure B.5 – Electrical analogue model based on a tube model Figure B.6 – Comparison between the measured (solid line) and the simulated(dashed line) transfer impedance |
| 42 | Figure B.7 – Frequency responses of simulated 0,4 cm3 coupler inputand transfer impedances |
| 43 | Bibliography |
