Audioscan Verifit - Manual (Page 48)

Verifit ® User's Guide Version 3.12  May 2015
used. See ANSI S3.22-1996 facts and ANSI S3.22-2003 facts. The [Input/Output] test allows you to generate up
to 4 separate input/output curves at each of 5 individual frequencies (250, 500, 1000, 2000, 4000 Hz) as
provided in ANSI S3.22.
1. Press <Tests>, then highlight and <PICK> [Test box measures], then highlight and <PICK> [Input/Output].
2. Refer to Coupling the hearing instrument, Positioning the hearing instrument and Battery pill use and care to
prepare the instrument for testing.
3. Turn the instrument ON; set AGC controls or programming parameters as in ANSI 1996 Linear and AGC
tests or ANSI 2003 Linear and AGC tests
4. Highlight and <PICK> [Curve 1]. Test setup instructions will be displayed.
5. Press <Continue> to generate a set of 5 input/output curves.
6. To measure another set of 5 input/output curves, highlight and <PICK> another [Curve #].
7. To summon a cursor to determine curve values, position the mouse pointer on a graph area and click the left
mouse button. Click again to turn it off.
NOTE: Noise in the test area may cause erroneous results at low input levels (particularly at 250 and 500 Hz).
Ensure that the test box is well sealed and ambient noise is low.
ANSI telecoil terminology
The Verifit test chamber contains an integrated telephone magnetic field simulator (TMFS) and a telecoil test
loop, meeting the requirements of ANSI S3.22, that enable the measurement of coupler SPL produced by a
hearing instrument with a telephone pickup coil. ANSI uses the following terms in telecoil testing:
RTG (reference test gain) is the average gain measured with the gain control in the reference test position
(1996) or reference test setting (2003). See ANSI S3.22-1996 facts and ANSI S3.22-2003 facts.
TMFS (Telephone magnetic field simulator). A 38.4-mm diameter coil spaced 16.5 mm below a test surfaced
driven by a specified test signal. Intended to simulate a telephone handset receiver.
SPLITS (Coupler SPL for an inductive telephone simulator). SPL developed in a 2cc coupler by a hearing
instrument with the gain control in the RTP (1996) or RTS (2003) when the input is the magnetic field generated
by a TMFS.
HFA (or SPA) –SPLITS. Average of the SPLITS at HFA or SPA frequencies.
STS (1996 - simulated telephone sensitivity) or RSETS (2003 - relative simulated equivalent telephone
sensitivity) is calculated as HFA (or SPA) SPLITS minus (RTG + 60). A positive STS or RSETS indicates
greater output when using the telephone than when using the microphone.
SPLIV (Coupler SPL in a vertical magnetic field). SPL developed in a 2cc coupler by a hearing instrument,
positioned as worn, with the user gain control in the RTP (1996) or RTS (2003) when the input is a 31.6 mA/m
vertical magnetic field.
HFA (or SPA) – SPLIV. Average of the SPLITS at HFA or SPA frequencies.
TLS (1996 - test loop sensitivity) or RTLS (2003 - relative test loop sensitivity) is calculated as HFA (or SPA)
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