FONIX® 8000 - Frye Electronics

70 FONIX 8000 Hearing Aid Test System
Figure 3.4.6—Measuring a three frequency average
3.4.7 Measuring Harmonic Distortion
Harmonic distortion is when the hearing aid returns energy at frequencies not
present in the source signal. The FONIX 8000 Test System allows you test for
this phenomenon very easily.
1. Press [MENU] from the Coupler screen.
2. Select Distortion under Measurement Settings using the [, ] buttons.
3. Select the distortion type desired by using the [, ] buttons.
The selections are:
2ND: Distortion present at the second harmonics, or twice the presented
frequency.
3RD: Distortion present at the third harmonics, or three times the presented
frequency.
TOTAL: Distortion present at the second and third harmonics.
4. Press [EXIT].
5. Use [F5] to select a signal type of TONE NORMAL. (Press [F5]. Use [, ]
to select TONE NORMAL. Use [] to complete the selection and close the
pop-up menu.)
6. Press [START] to run normal frequency sweep.