FONIX® FP35 Touch - Frye Electronics

Coupler Measurements 67
3.3.3 Setting up a Body Aid
Press down on the blue adhesive
putty with a pencil or your finger to
create an acoustic seal between the
aid and coupler.
You may want to double-check the
aid placement through the open
end of the coupler at this point.
Slowly insert the microphone into
the coupler. You may feel an initial
resistance when the mic reaches the
O-ring. Continue to push the microphone
until it stops.
Place the completed assembly over
the center of the speaker in the test
chamber. With ITEs, the position of
the aid can affect the frequency
response. Point the faceplate to the
right or left. Place the mic cable
between the arrows (secure it with a
bit of blue adhesive putty if necessary).
The Velcro on the coupler will
help hold the assembly in place. Be
consistent with your setup for repeatable
results.
Set the hearing aid’s gain control to
the desired position, and adjust the
source level to the desired amplitude.
Place the hearing aid into the sound chamber so that the microphone of the aid is
centered over the speaker. Adjust the tone and gain controls to the desired positions.
Insert the FP35 microphone into the HA-2 coupler and snap the receiver
onto the end of the coupler (you will not need the ear level adapter for this
setup). Place the coupler outside the sound chamber and close the lid if possible.
Adjust the source level to the desired test drive amplitude.
3.4 Frequency Responses
In the Coupler Multicurve Mode of the FP35, you can perform the following measurements:
response curves, single-frequency measurements, harmonic distortion,
and intermodulation distortion.