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RM500SL
To test frequency-lowering:
1. From the Speechmap screen, choose either "On-ear" or "Test box" Mode. (Review 17.9:
On-ear or Test box Mode.)
2. Program the hearing instrument so that the frequency-lowering feature is inactive.
3. Select "Test 1" and choose 65dB from the level menu.
4. Choose Speech3150, Speech4000, Speech5000 or Speech6300 from the stimulus menu.
Note that only the LTASS is shown for these stimuli and targets (if selected) have been
suppressed.
5. Press "Continue" to measure and store the long-term signal-averaged result. If the
isolated band does not appear in the Test 1 curve, it may indicate that the hearing aid
has no gain at the selected band frequency. This does not mean that the hearing aid will
be unable to transpose the band to a lower frequency when frequency lowering is
enabled.
6. Program the hearing instrument to activate the frequency-lowering feature.
7. Select "Test 2" and select the same stimulus and stimulus level used in Test 1.
8. Press "Continue" to measure and store the long-term signal-averaged result.
9. The isolated band should now appear at a lower frequency and should reach or exceed
threshold at its new location as shown below. Note that the "cavity" between 1 kHz and
the isolated band may be partially or completely filled in by noise within the hearing aid
which will make the isolated band appear less distinct in the test curves.
10.Once the frequency-lowering properties of the hearing instrument have been verified,
User's Guide Version 3.4 © June 2011
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