66 FONIX FP40 Portable Hearing Aid Analyzer
4.4.1 Setting up for the test
Follow the instructions found in Section 4.2.1 for instructions on setting up the aid for testing.
To enter the ANSI 92 screen:
1. From the Main Coupler Screen, look at the FP40’s display above the F4 function key. If it says
“AN92” , skip to step 6.
2. Press F1—Menu.
3. Use the AMPLITUDE and FREQUENCY knobs to select MAIN F4 under FUNCTION KEY
DEFIN.
4. Press START/STOP to choose AN92. This will let you use the F4 function key to enter the
ANSI 92 screen from the Main Coupler Screen.
5. Press F1 to return to the Main Coupler Screen.
6. Press F4 to enter the ANSI 92 screen.
To change the ANSI 92
settings:
1. Press F2 to select the desired range of input levels for the frequency response curves.
2. Press F3 to select the settling time. This is the amount of time that the analyzer presents the
Composite signal before taking the measurement. You should choose a value twice the pub
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lished attack specification.
3. Press F6 to choose the amount of noise reduction used for the measurements. See Section
2.4.2.2.
4. Press F7 to select the type of battery pill used. If you don’t want to test the battery current
drain of the aid, you can ignore this selection.
4.4.2 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 4.2.1.
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. For most aids, the analyzer will pause after performing sev
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eral measurements in order for you to turn down the gain of the aid.
6. If the analyzer pauses, 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.
7. Press START/STOP to complete the test sequence.
