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.<\/p>\n
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| 4<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 1 Scope 2 Normative references 3 Terms, definitions and abbreviated terms 3.1 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 3.2 Abbreviated terms 4 Mechanical design of the 0,4 cm3 coupler 4.1 General <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 4.2 Cavity dimensions 4.2.1 Critical dimensions 4.2.2 Effective coupler volume Figures Figure 1 \u2013 Mechanical design of the 0,4 cm3 coupler, shown with removable coupling plate with a nipple for the attachment of coupling tubing <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 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 <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 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 <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 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\u00a02 \u2013 Coupling to a hearing aid receiver by means of coupling tubing <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 6.3 Coupling to a receiver in the canal (RIC hearing aid) Figure 3 \u2013 Coupling to an ITE hearing aid <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 6.4 Coupling to a BTE hearing aid with 2 mm continuous internal diameter tubing Figure 4 \u2013 Coupling to a receiver in the canal (RIC hearing aid) <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 6.5 Coupling to a BTE hearing aid with earmould simulator Figure 5 \u2013 Coupling to a BTE hearing aid with 2\u00a0mm continuous internal diameter tubing <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 6.6 Coupling to a BTE hearing aid with thin tubing Figure 6 \u2013 Coupling to a BTE hearing aid with earmould simulator <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 7 Transfer impedance of the 0,4 cm3 coupler Figure 7 \u2013 Coupling to a BTE hearing aid with thin coupling tubing <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 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 \u2013 Magnitude frequency response of the transfer impedance\u00a0\uf0b4\u00a0frequency and the related equivalent volume <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 8.2 Comparison of the coupler impedance with typical source impedances Figure 9 \u2013 Comparative measurement of the 0,4 cm3 coupler, the 2 cm3 coupler and the occluded-ear simulator frequency responses <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 8.3 Influence of sound source impedance on measured level difference between the 0,4 cm3 coupler and the 2 cm3 coupler Figure\u00a010 \u2013 Magnitude frequency responses of acoustic impedance of the 2\u00a0cm3, the 0,4\u00a0cm3 coupler and various hearing aid types <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 9 Maximum permitted expanded uncertainty for coupler conformance testing Figure 11 \u2013 Deviation from the normalized coupler volume ratio as a function of the effective volume of the sound source Vs <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 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 \u2013 Values of Umax for basic measurements <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 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 \u2013 Distortion test frequencies and input sound pressure levels <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | Table 3 \u2013 Values of Umax for basic measurements <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 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 \u03bb\/2 resonances <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | Figure A.1 \u2013 Electrical analogue model of the human ear <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | A.3 Measured and simulated transform responses of a standard-fitting Figure A.2 \u2013 Measured transform response of a standard-fitting <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | A.4 Transform curves for CIC-fitting and deep-insertion-fitting Figure A.3 \u2013 Comparison between the measured and the simulated standard-fitting transform response <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | Figure A.4 \u2013 Transform responses for (a) standard-fitting, b) CIC-fittingand (c) deep-insertion-fitting <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | Table A.1 \u2013 Transform data for standard-fitting (fitting at reference plane), CIC-fitting and deep-insertion-fitting <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | 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 <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | 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 <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | B.2 Measurement of the coupler transfer impedance Figure B.1 \u2013 Test set-up for measuring the coupler transfer impedance Figure B.2 \u2013 Average frequency response of 8 coupler measurements <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | Figure\u00a0B.3 \u2013 Average transfer impedance of the 0,4\u00a0cm3 coupler Figure B.4 \u2013 Transfer impedance times frequency re 1\u00a0Pa\/m3 in dB and as equivalent volume in mm3 in the frequency range 100\u00a0Hz to 60\u00a0kHz <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | Table B.1 \u2013 Transfer impedance of the 0,4\u00a0cm3 coupler in the frequency range from 100\u00a0Hz to 60\u00a0kHz <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | B.3 Electrical analogue representation of the coupler as a tube model <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | Figure B.5 \u2013 Electrical analogue model based on a tube model Figure B.6 \u2013 Comparison between the measured (solid line) and the simulated(dashed line) transfer impedance <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | Figure B.7 \u2013 Frequency responses of simulated 0,4 cm3 coupler inputand transfer impedances <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Electroacoustics. Hearing aids. Method for measuring electroacoustic performance up to 16 kHz<\/b><\/p>\n |