51
Section 2: RealEar evaluation with FM system
4. Press
[MENU].
5. Highlight MODE with [
∨
,
∧
].
6. Select PURE TONE with [<, >].
7. Highlight GAIN(G)/SPL with [
∨
].
8. Select G/REF OFF with [<, >].
9. Press [MENU] to return to the Insertion Gain Screen.
10. If necessary, use [<, >] to set the FREQUENCY to 1000 Hz in the CURRENT STATUS
box.
11. Press [START/STOP] to begin a single tone continuous measurement.
12. Use [
∨
,
∧
] to adjust signal level to 65 dB.
13. Record the MIC OUT reading in the CURRENT STATUS box. This is the “Hearing
Aid Output” at 65 dB SPL at 1000 Hz. See Figure 2.3.1.
14. Press [START/STOP] to stop the measurement.
2.3.2 Single frequency response of FM mic at 65 dB SPL
1. Set up the FM system as described in Section 2.1.2. Set the FM to receive FM+ENV.
2. Press [START/STOP] to begin a single tone continuous measurement.
3. Note the MIC OUT reading in the CURRENT STATUS box. This is the “FM Output.”
4. Adjust the FM receiver volume control so that the FM Output matches the Hearing
Aid Output found in Section 2.3.1. Now the gain of the hearing aid and the FM sys-
tem have been matched.
5. Press [START/STOP] to stop the measurement.
2.3.3 Verify increase in signal level
1. Press [START/STOP] to begin a single tone continuous measurement.
2. Use
[
∧
] to adjust the signal to 80 dB SPL.
3. Note the AID OUT on the left side of the screen, below the graph. This is the FM
Output.
4.
Compare the Hearing Aid Output (from Section 2.3.1) and the FM Output and adjust
the FM receiver volume control if necessary according to the following:
If the increase is:
• 10 dB, no further adjustments are needed.
• 15 dB, reduce the FM receiver volume control so that the FM Output falls by 5 dB.
