Audioscan Verifit - Manual (Page 6)

Verifit ® User's Guide Version 3.12  May 2015
1 About Verifit
This section provides a listing of features new in this software release, describes the Audioscan Verifit, provides
contact, warranty and trademark information, safety warnings and notices and instructions for accessing the
electronic User’s Guide.
Note that the User's Guide may be viewed on the Verifit at any time by pressing . (For long Help pages,
use (or mouse) to switch between the Help index and the Help page and
arrows (or mouse) to
scroll through the page).
New in this software release
Software 3.12 introduces the following significant additions and changes:
1. NAL-NL2 prescription formula. For details, see 17. NAL-NL2 in Speechmap.
2. User-supplied test signals. For details see 17. Using custom stimuli in Speechmap
3. Inductive stimulus in Speechmap for adjusting tcoils for use with room loops. For details see 18. T-Loop
fitting and verification in Speechmap.
4. New Directional Test works with feedback cancelers and frequency-lowering devices.
5. Improved audioscan updater. USB memory sticks left plugged in will not interfere with startup.
Product description
The Verifit is a hearing aid analyzer intended to be used by hearing care professionals such as audiologists and
hearing aid specialists to verify the electro-acoustic performance of a hearing aid connected to a standard
earphone coupler or while worn on the ear of the end user. It consists of:
a) an acoustically-treated test chamber which houses a battery substitute (1.3 volt supply), 2 loudspeakers, a
reference microphone for controlling the signal from the loudspeakers, a standardized earphone coupler
connected to a measuring microphone for the purpose of measuring the sound level produced in the standard
coupler by a hearing aid and a custom keypad.
b) an analyzer/display unit housing a flat-panel video display, power supply, signal generation, measurement
and control electronics and two sound-field loudspeakers.
c) two real-ear measurement microphone assemblies, each housing a reference microphone for controlling the
signal from the sound-field speakers and a probe microphone connected to a thin silicone tube which may be
inserted into the ear canal for the purpose of measuring the sound level in the ear canal produced by a hearing
aid.
d) a miniature earphone used to measure the real-ear to coupler difference (RECD) useful in estimating the
sound level produced in an individual ear from measurements in the standard earphone coupler.
The analyzer attaches to the acoustic test chamber via two 15-conductor cables. The acoustic test chamber
provides connectors for the microphones used for controlling the stimulus and measuring the response. For HIT
mode, a reference microphone, coupler microphone and a battery simulator are normally connected via
connectors provided inside the acoustic test chamber. For REM mode, two probe modules – each containing a
reference microphone and a measurement microphone, and a real-ear to coupler difference (RECD) earphone
are normally connected via connectors situated on the front of the acoustic test chamber. A connector and
volume control for headphones, used to monitor coupler and probe microphone signals, are provided on the front
right side of the test chamber.
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