audioscan Verifit VF-2 - Fitting to Targets for Loud Sounds; Fitting to Targets for Mid-Level Speech

Verifit
®
User's Guide Version 3.12  November 2015
Fitting to targets for loud sounds
4. Select Test 2 & set stimulus to [MPO]. In test box mode, 90 dB tone bursts are presented at 1/3 octave
frequencies in a repeating sequence. In on-ear mode, a single sequence of 85 dB tone bursts is presented
when you press <Continue>.
5. In test box mode, adjust high-level gain and/or output limiting (e.g.,MPO, PC) so the curve matches the +
REAR90 targets (DSL) or approaches but doesn’t exceed the RESR targets (NAL-NL1, NAL-NL2) at all
frequencies. Press <Continue> to record the MPO curve. In on-ear mode, advise the client to point to the
screen if a sound becomes too loud during the test (see Max TM SPL setup). Press <Continue> to run and
record a single sweep. Adjust the gain and output for loud sounds as for test box measures, factoring in client
response. Repeat as necessary.
Running a new test may automatically hide the speech envelope of the previous test, depending on the option
chosen in Setup (see Speechmap - Speechmap Setup). To redisplay, highlight and <PICK> Hide/Show, then
highlight and <PICK> the envelope display (right column) button for the test.
Fitting to targets for mid-level speech
6. Select Test 3 and set stimulus to [Speech-ISTS], [Speech-std(1)] or [Speech-std(2)] and level to 70.
Elongated + symbols show the target range for 70 dB speech LTASS.
7. Adjust gain for mid-level sounds so that the middle curve (the LTASS) falls within the target range. Press
<Continue> to run the complete passage. Repeat as necessary. Achieving this goal may require adjusting
gain for soft speech, which will reduce its audibility. This may be a necessary compromise with some
hearing instruments and for clients with a very narrow dynamic range.
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