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0611 RM500SL User’s Guide Version 2.8 Page 39
8.3 ANSI S3.22-2003 facts
FastFacts 8.3: ANSI S3.22-2003 facts
8.4 ANSI 1996 Linear and AGC tests
FastFacts 8.4: ANSI 1996 Linear and AGC tests
1)
Press <Tests>, then highlight and <PICK> [Linear] or [AGC].
2) Highlight and <PICK> [Start test]; test setup instructions will be displayed.
3) Refer to 7.11: Coupling the hearing instrument, 7.12: Positioning the hearing
instrument and 2.5: Battery pill use and care to prepare the instrument for
testing.
4) Turn the instrument ON.
5) Set the gain control (manual or programmable) to maximum with all other
controls set to provide the widest frequency response, greatest gain and
highest maximum output. AGC controls and/or programmable parameters
should be set as designated by the manufacturer.
6) Press <Continue> to run the test or press <Cancel> to abort the test. Note
that, if required, the RM500SL will pause during the test to request that the
volume control be adjusted to the Reference Test Position (RTP). Open the
HIT chamber if necessary and, without moving the hearing instrument, adjust
the user gain control until the large vertical arrow on the screen prompt
disappears. Press <Continue> to resume the test.
If you are unsure which test sequence to run, try [AGC] first. If attack and release
times are all near zero, the instrument is probably linear.
ANSI S3.22-2003 has been designated a recognized standard by the FDA but is
not yet mandatory. Manufacturers may use either version for reporting test data.
The most significant change from the 1996 version is the requirement for the
hearing aid to be set in its most linear mode for the setting of the gain control to
Reference Test Setting (changed from Reference Test Position) and for all tests
except attack and release and input-output (I/O) curves. These two tests are to be
conducted with the AGC function set for maximum effect. The AGC test sequence
will pause to allow AGC to be set prior to measuring attack and release time.
Full-on gain is determined with 50 dB input SPL (60 dB was formerly an option)
and frequency response curves are run at 60 dB SPL for Linear and AGC aids.
The OSPL90 curve, the HFA (or SPA) and peak value of this curve, the frequency
of the peak, the HFA (or SPA) full-on gain are determined at full-on gain setting.
The response curve, frequency range, Reference Test Gain, battery drain,
equivalent input noise, distortion, attack and release times are determined at RTS.
These changes result in more consistent values for reference test gain, equivalent
input noise and attack and release time. See 7.6: 1996 or 2003 ANSI standard,
8.2: ANSI S3.22-1996 facts and 8.5: ANSI 2003 Linear and AGC tests.