AS 1088.8-1987

1 - AS 1088.8-1987 HEARING AIDS - METHODS OF MEASUREMENT OF PERFORMANCE CHARACTERISTICS OF HEARING AIDS UNDER SIMULATED IN SITU
4 - PREFACE
5 - CONTENTS
7 - 1. Scope
7 - 2. Object
7 - 3. Limitations
8 - 4. Explanation of terms
8 - 4.1 Sound pressure level
8 - 4.2 Pinna simulator
8 - 4.3 Ear simulator
8 - 4.4 Occluded-ear simulator
8 - 4.5 Ear canal extension
8 - 4.6 Ear insert simulator
8 - 4.7 Manikin (head and torso simulator)
9 - 4.8 Reference point of a subject or manikin
9 - 4.9 Plane of symmetry of the manikin
9 - 4.10 Axis of rotation of the manikin
9 - 4.11 Reference plane of the manikin
9 - 4.12 Test point
9 - 4.13 Reference input sound pressure level
9 - 4.14 Test axis
9 - 4.15 Test plane (for measurement of the uniformity of the free field wavefront)
9 - 4.16 Azimuth angle of sound incidence
9 - 4.17 Elevation angle of sound incidence (a)
10 - 4.18 Reference position of the manikin in the test space
10 - 4.19 Manikin unoccluded ear gain
10 - 4.20 Manikin unoccluded ear gain frequency response (MFR)
10 - 4.21 Simulated in situ gain (SISG)
10 - 4.22 Simulated in situ gain frequency response (SISGFR)
10 - 4.23 Simulated insertion gain (SIG)
10 - 4.24 Full-on simulated insertion gain
10 - 4.25 Simulated insertion gain frequency response (SIGFR)
10 - 4.26 Manikin unoccluded-ear directional response (MDR)
10 - 4.27 Simulated in situ directional response (SISDR)
11 - 4.28 Simulated insertion directional response (SIDR)
11 - 4.29 Simulated in situ OSPL 90 (output sound pressure level for 90 dB input SPL)
11 - 4.30 Simulated in situ OSPL 90 frequency response
11 - 5. Test equipment
11 - 5.1 Acoustical requirements for the test space
11 - 5.2 Sound source
12 - 5.3 Manikin
12 - 5.4 Ear simulator
12 - 5.5 Ear insert simulator
12 - 5.6 Equipment for the measurement of occluded-ear simulator sound pressure level
13 - 5.7 Equipment for automatic sweep frequency recording
13 - 5.8 Equipment for calibration of free field sound pressure level
13 - 6. Test conditions
13 - 6.1 Choice of test point
14 - 6.2 Ambient conditions
14 - 6.3 Manikin
14 - 6.4 Location of the hearing aid
14 - 6.5 Normal operating conditions for the hearing aid
15 - 7. Measurements
15 - 7.1 General
15 - 7.2 Adjustment of the reference input sound pressure level
16 - 7.3 Manikin frequency response (MFR)
16 - 7.4 Full-on simulated insertion gain measured by the constant reference input SPL method
17 - 7.5 Full-on simulated insertion gain measured by the constant ear simulator SPL method
18 - 7.6 Directional characteristics
19 - 7.7 Simulated in situ OSPL 90 measurements
19 - 8. Frequency response recording charts
22 - APPENDIX A - GENERAL REQUIREMENTS FOR A MANIKIN