Frye FONIX 7000 - Manual (Page 73)

Basic Sound Chamber Tests
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Figure 3.3.5A—Coupler setup Figure 3.3.5B—Body Aid in test chamber
3.3.6 Eyeglass Aids
1. Follow the manufacturer’s instructions for removing the hearing aid assem-
bly or the temple piece from the eyeglass frame, if possible. Should you be
unable to remove the aid assembly or temple from the frame, it is possible
to place the entire frame in the test chamber for testing. Be sure to fold the
glasses first.
2. Insert the coupler microphone into the HA-2 coupler.
3. Couple the aid to the 2-cc coupler using the BTE aid adapter and the appro-
priate tubing, as shown in Figure 3.3.6.
The length and thickness of the tubing have a significant effect on the fre-
quency response of an aid, especially in the 500 to 1000 Hz region. If an
aid is being compared against the manufacturer’s specifications, the tubing
should be carefully chosen to duplicate that used by the manufacturer to
obtain the original data. For ANSI tests, use 0.6" (15 mm) of #13 thick-
walled tubing (exposed portion).
4. Position the microphone of the aid as close as possible to the reference
point in the test chamber, as shown in Figure 3.3.6.
5. Close the lid, if possible, and then test as desired. If the lid can’t be closed,
measurements can be made with the lid open. But we recommend that you
first re-level the chamber with the lid open, and use the quietest possible
location.