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Section 1: Coupler Tests of FM Systems
1.2 Omni-directional: FM-only
This section contains a description of the four different coupler measurements of FM systems
when the client primarily uses the system in FM-only mode. These measurements are:
• EHA65: typical electroacoustic response of the aid
• EFM80: typical electroacoustic response of the FM transmitter/receiver
• EHA90: saturation electroacoustic response of the aid
• EFM90: saturation electroacoustic response of the FM transmitter/receiver
1.2.1 Test aid alone with typical input — EHA65
1.
Set up the hearing aid according to the hearing aid setup described in Section 1.1.2.2.
Press [RESET] to enter Composite Weighted Gain Mode.
3.
Press [WEIGHT] to enter Composite Weighted Power Mode. The display will be
labeled as OUTPUT SPL.
4.
Use [
∨
] to set RMS Source to 65 dB SPL.
5. Once the curve is stable, press [FREEZE] to pause the measurement. If the 6500-CX
has the Multi-Curve Option, press [START] (not [CONTINUE]!) to save the curve
into the Multi-Curve stack. For units without Multi-Curve, press [CRT] to print the
measurement.
6.
This will be referred to as the Electroacoustic Hearing Aid Response or EHA65. See
Figure 1.2.1.
Figure 1.2.1
EHA65—hearing aid response at 65 dB SPL
