19
Section 1: Coupler Tests of FM Systems
f. If necessary, use [<, >] to display CRV 2 in the second slot. This curve is EHA65.
If you don’t have the Multi-Curve Option, press [CRT] to print out EFE80 and com-
pare it to EHA65.
Figure 1.3.5
Comparison of EHA65 (CRV2), the hearing aid response at 65 dB
SPL and EFM80 (CRV1), the FM response at 80 dB SPL
5. Compare EHA65 (CRV 2) to EFE80 (CRV 1) to confirm that the desired FM advan-
tage is maintained over the 500 to 2000 Hz range. In general, that advantage should
be 7-10 dB. See Figure 1.3.5.
6. For units with Multi-Curve, you will want to save EFE80 for a comparison in the
next section. To do this:
a. Press [CONTINUE] twice to exit from Multi-Curve.
b. Press [FREEZE] to save the current EFE80 measurement.
c. Press [START] to save the curve to the Multi-Curve stack. EFE80 has just become
CRV 2 and EHA65 has just become CRV 3. You will use them in the next section.
