BS EN 60118-15:2012
$167.15
Electroacoustics. Hearing aids – Methods for characterising signal processing in hearing aids with a speech-like signal
| Published By | Publication Date | Number of Pages |
| BSI | 2012 | 36 |
IEC 60118-15:2012 specifies a test signal designed to represent normal speech, the International Speech Test Signal (ISTS), together with the procedures and the requirements for measuring the characteristics of signal processing in air-conduction hearing aids. The measurements are used to derive the estimated insertion gain (EIG). For the purposes of characterizing a hearing aid for production, supply and delivery, the procedures and requirements to derive the coupler gain on a 2 cm 3 coupler as defined in IEC 60318-5 are also specified. The purpose of this standard is to ensure that the same measurements made on a hearing aid following the procedures described, and using equipment complying with these requirements, give substantially the same results. Measurement methods that take into account the acoustic coupling of a hearing aid to the individual ear and the acoustic influence of the individual anatomical variations of an end-user on the acoustical performance of the hearing aid, known as real-ear measurements, are outside the scope of this particular standard.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 6 | English CONTENTS |
| 8 | INTRODUCTION |
| 9 | 1 Scope 2 Normative references |
| 10 | 3 Terms and definitions |
| 11 | 4 Limitations 5 Setup 5.1 System overview |
| 13 | 5.2 Estimated insertion gain Figures FigureĀ 1 ā Measurement setup for the estimated insertion gain |
| 14 | 5.3 Coupler gain 6 Test equipment 6.1 Acoustical requirements FigureĀ 2 ā Measurement setup for the coupler gain |
| 15 | 6.2 Test signal 6.2.1 Specification of ISTS |
| 16 | 6.2.2 Shaping of the test signal for determining the EIG FigureĀ 3 ā ISTS 30th, 65th, 99th percentiles and LTASS in dB versus one-third-octave bands Tables TableĀ 1 ā ISTS 30th, 65th, 99th percentiles and LTASS in dB at one-third-octave bands |
| 17 | 6.3 Earphone coupler and attachments 6.3.1 Estimated insertion gain 6.3.2 Coupler gain 7 Test conditions 7.1 Programming of hearing aid |
| 18 | 7.2 End user settings for programming 7.2.1 Hearing aid features 7.2.2 Vent selection for programming 7.2.3 Directionality 7.3 Audiograms for a typical end-user |
| 19 | FigureĀ 4 ā Standard audiograms for the flat and moderately sloping group TableĀ 2 ā Standard audiograms for the flat and moderately sloping group |
| 20 | 8 Measurements and analysis 8.1 Measurements 8.1.1 General FigureĀ 5 ā Standard audiograms for the steep sloping group TableĀ 3 ā Standard audiograms for the steep sloping group |
| 21 | 8.1.2 Estimated insertion gain (EIG) 8.1.3 Coupler gain (optional for 2Ā cm3 coupler) 8.2 Analysis 8.2.1 General |
| 22 | FigureĀ 6 ā Overview of analysis |
| 23 | 8.2.2 Compensating for hearing aid processing delay 8.2.3 Correction for use of 2 cm3 coupler for EIG determination 8.2.4 Calculation of the estimated insertion gain for the LTASS of the ISTS (LTASSĀ EIG) FigureĀ 7 ā Time alignment of output signal (y) relative to the input signal (x) TableĀ 4 ā Recommended coupler correction values when using the 2Ā cm3 coupler |
| 24 | 8.2.5 Calculation of the coupler gain for the LTASS of the ISTS (LTASS coupler gain) (optional) 8.2.6 Sectioning of recorded signals for percentile calculations FigureĀ 8 ā Sectioning of recorded signals |
| 25 | 8.2.7 Calculation of the EIG for the 30th, 65th and 99th percentiles of the ISTS (percentile EIG) 8.2.8 Calculation of the coupler gain for the 30th, 65th and 99th percentiles of the ISTS (Percentile coupler gain) (optional) |
| 26 | 9 Data presentation 9.1 LTASS gain (LTASS EIG or LTASS coupler gain) FigureĀ 9 ā Illustration of the method for obtaining “time aligned gain”for the 65th percentile FigureĀ 10 ā LTASS gain at 3 input sound pressure levels |
| 27 | 9.2 Percentile gain (percentile EIG or percentile coupler gain) FigureĀ 11 ā LTASS gain at 3 input levels relative the LTASS gain at 65Ā dB input sound pressure level FigureĀ 12 ā Percentile gain for 3 percentiles and corresponding LTASS gain |
| 28 | 9.3 Interpretation of gain views 9.3.1 LTASS gain view 9.3.2 Percentile gain view |
| 29 | 9.4 Mandatory data |
| 30 | Annex A (informative) International speech test signal (ISTS) |
| 33 | FigureĀ A.1 ā ISTS level distributions for five third-octave bands as measured from 50Ā % overlapping 125Ā ms sections of the ISTS |
| 34 | Bibliography |
