Automated Test Sequences
69
4.5.3 Running the test sequence
1. Level the sound chamber if necessary. See Section 3.2 for details.
2. Set up the aid for testing. See Section 4.5.1.
3. Close the sound chamber.
4. Press START/STOP when you are ready to begin the test.
5. Wait for several tests to be run. The analyzer will pause after performing several measure-
ments in order for you to turn down the gain of the aid.
6. Open the sound chamber and adjust the gain control of the aid until the MEASURED gain
matches the TARGET gain to within 1 dB when the sound chamber is closed.
Note:
If you prefer, you can set the target reference gain to match the manufacturer’s speci-
fications as the IEC 118-7 standards instructs instead of using the FP40’s calculated target
value. However, we have never found any difficulties with using the FP40’s calculated target
reference gain.
7. Press START/STOP to complete the test sequence.
8. If you have chosen to measure an I/O curve, press the DATA/GRAPH button to display the
measurement.
4.5.4 Viewing the results
See Figure 4.5.4 for an example of IEC results.
1. Response curve at 60 dB SPL
2. OSPL90: Measurement at the reference test gain of 90 dB SPL
3. MAX: Maximum frequency response measured and the frequency at which it occurred
4. REFERENCE TEST GAIN CALCULATED
5. REFERENCE TEST GAIN MEASURED
6. TOTAL HARMONIC DISTORTION
7. EQIV INPUT NOISE: Equivalent input noise
8. BATTERY: Battery current drain
9. OSPL90 Curve: Response curve taken at 90 dB SPL
10. FOG 50: Full-on gain response curve taken at 50 (or 60) dB SPL
11. I/O curve: Input/output measurement taken at the reference test frequency