Verifit
®
User's Guide Version 4.8
©
November 2016
To test directional function in situ, see On-Ear Instrument Measures.
Multicurve procedure
Multicurve generates 1 to 4 output or gain response curves using either pink noise or swept pure tones at input
levels ranging from 40 – 90 dB SPL and 0 dB (off).
Multicurve allows the use of the 2cc HA-1 coupler or the 0.4cc Audioscan Wideband Coupler (AWC). The
HA-1 coupler is not useful at high frequencies because of resonances and low signal levels. The use of the
AWC is desirable because it raises the high frequency SPL of the hearing aid by more than 20 dB, making the
rising noise floor of the coupler microphone less significant.
1. Right-click to raise the Home prompt and select [Multicurve] from under Test box.
2. Refer to Test Box Measures – Setup for connecting the hearing instrument to the coupelr microphone.
3. Ensure the hearing instrument is powered and turned on.
4. Select test 1, 2, 3, or 4 by pressing the respective
button.
5. Select [Stimulus] and pick either Pink noise or Swept.
6. Select [Level] and pick a stimulus output level.
7. Click
to run a sweep or to capture a pink noise curve. Click
to abort the test.
8. To measure another response curve, click another test. Existing test data will be overwritten.
9. To change scale from dB SPL to dB Gain, highlight and select the Scale window.
Multicurve results
1.
Output
curves for the noise signal are in 1/12th octave bands. They will be approximately 19 dB lower than
pure tone curves for a linear instrument.
2.
Gain
curves for a linear instrument will be the same for both swept and pink noise test signals.
3. For compression instruments, both gain and output curves may be expected to differ for the two test signals.
4. See Test Box Measures - Setup to change screen appearance.
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Summary of Contents for verifit
Page 1: ...Audioscan Verifit User s Guide 4 8 November 2016...
Page 17: ...Verifit User s Guide Version 4 8 November 2016 EC Declaration of Conformity 17...
Page 92: ...Verifit User s Guide Version 4 8 November 2016 92...
Page 94: ...Verifit User s Guide Version 4 8 November 2016 94...
Page 107: ...Verifit User s Guide Version 4 8 November 2016 Telecoil test results 107...
Page 123: ...Verifit User s Guide Version 4 8 November 2016 123...
Page 148: ...Verifit User s Guide Version 4 8 November 2016 148...
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