Audio Traveler AA222, Инструкции по эксплуатации

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AA222 Operation Manual Page 20
Reflex Decay Interpretation
Figure 4:
Reflex Decay:
Reflex decay is calculated as the reduction of size of the
acoustic reflex during the first 10 seconds of muscular
contraction. Most normal ears will be able to maintain a
Stapedius contraction for 10 seconds or longer for frequencies
below 1000Hz, at a level 10dB above reflex threshold. A high
reflex decay score could indicate VIIIth nerve disorders.
Another way of stating the reflex decay is by finding the number
of seconds it takes before the Stapedius contraction falls to 50%
of its initial maximum.
Note: If a decay score is obtained, you should assure that it is
not due to an improper seal, which might produce an artefact
similar to a decaying curve. See the chapter “Preparing the
Test” for details of fitting the probe.
The fact that the light band of the probe goes off, and the test
starts is not an absolutely certain indication of a fit good enough
to produce valid decay test results. This is due to the prolonged
test time and the high sensitivity of the test.
Also great care should be taken to have the probe kept in a very
fixed position relative to the ear during testing.