Audioscan Verifit 2 - Manual (Page 36)

Verifit ® User's Guide Version 4.2 © June 2015
5 On-Ear Measures - Setup
For accurate, repeatable measurements, the Verifit must be properly set up and calibrated, the client must be
properly positioned and the probe tube must be properly positioned in the ear canal. Some common terms:
Real-Ear Unaided Response (REUR): SPL, or band SPL, in the open (unaided) ear canal for a given stimulus.
Real-Ear Unaided Gain (REUG): Difference, in dB, between the REUR and the stimulus SPL, or stimulus band
SPL.
Real-Ear Aided Response (REAR): SPL, or band SPL, in the ear canal for a given stimulus, with a working
hearing aid in place.
Real-Ear Aided Gain (REAG): Difference, in dB, between the REAR and the stimulus SPL, or stimulus band
SPL.
Real-Ear Saturation Response (RESR): The REAR obtained using a narrow-band signal at a level high enough to
saturate the hearing aid (usually 85 - 90 dB SPL).
Real-Ear-to-Coupler Difference (RECD): Difference, in dB, between the SPL produced in the ear canal and the
SPL produced in a coupler by the same sound source.
Audioscan Wideband Coupler (AWC): A cylindrical coupler having a volume of 0.4 cc.
Thin-tube and Receiver In Canal (TRIC) adapter: Silicone attachment to the AWC which accepts the nozzle of a
thin-tube or RIC type hearing aid. It will also accept the nozzle of the RECD transducer, an ER-3A insert
earphone and #13 standard earmold tubing.
Wideband Real-Ear-to-Coupler Difference (WRECD): The difference in SPL produced in an occluded ear canal
and in the 0.4cc coupler by a high impedance coupled sound source.
External sound-field speaker setup
In some installations, the internal sound-field speakers may not be convenient or may yield speaker overdriven
errors because of severe standing waves from nearby walls or shelves. In these cases, an external speaker having
a smooth response from 200 - 16000 Hz and an impedance of 4 ohms or greater may be connected to the Front
on-ear measure speaker connector on the rear connector panel. The VA-111 speaker is available for this purpose.
The speaker should be mounted at ear height, well away from reflective surfaces. See Positioning the client.
To select this speaker:
1. Right-click to raise the home menu, then left-click [Speakers].
2. Toggle the Sound-field speaker button between [Internal] and [External].
3. Click to exit Setup
For on-ear directional tests, connect an external speaker (see requirements above) to the back on-ear speaker
connector on the rear connector panel. Position the back speaker directly behind and facing the back of the
client’s head so that front and rear speakers are at the same height and are at the same distance from the center
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