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Section 1: Coupler Tests of FM Systems
1.3.7 Test aid alone with high-level input — EHA90
1. Turn off the FM signal, and set up the hearing aid for testing as described in Section
1.1.2.
2. Press [SINE/COMPOSITE] button to enter Pure Tone Mode. The analyzer will auto-
matically set itself to a signal level of 90 dB SPL.
3.
Press [START] to begin the pure-tone sweep. The response will be stored in the
Multi-Curve stack when the measurement is complete. For instruments without the
Multi-Curve option, press [CRT] to print a hardcopy.
4.
This response will be referred to as the Electroacoustic Hearing Aid Saturation
Response or EHA90. See Figure 1.3.7.
Figure 1.3.7
EHA90—the hearing aid response at 90 dB SPL
1.3.8 Test with FM system using a high-level input — EFE90
1. Set up the FM system for testing according to Section 1.1.3. The FM receiver should
be set to receive FM+ENV.
2.
Press [START] to begin the pure-tone sweep. The response will be stored in the
Multi-Curve stack when the measurement is complete. For instruments without the
Multi-Curve option, press [CRT] to print a hardcopy.
3.
This response will be referred to as EFE90 or the Electroacoustic FM and
Environmental Response with 90 dB SPL input to the FM microphone.
