Otodynamics Otoport Lite, Руководство пользователя, Страница: 58 / 208

CHAPTER SEVEN
OAE test procedure
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OAE test procedure
7.1
Checkfit
7.1.1
Checkfit display
It is important to perform a test in the appropriate conditions. The Checkfit
screen allows a user to assess the testing environment. Conditions such
as high ambient noise, poor fit of the probe in the ear (including leaks) and
blocked probes can be detected before starting the test.
Excessive noise or a poor probe fit may mean that the test cannot be
performed or that the quality of data collected may be too low for an
accurate test result to be determined.
Fit size indicator
The Checkfit screen shows a Fit Size Indicator; this shows a series of ears
of increasing size, indicating increasing ear canal volumes. The size of ear
canal detected in Checkfit is indicated by an arrow.
During Checkfit the Otoport repeatedly plays a click at a fixed level and
records the sound level this click produces in the ear.
The sound level recorded depends on the fit of the probe and the size of
the ear canal in which the probe is inserted.
Ear canal size increases from birth to adulthood. So, given a good probe
fit, the sound level recorded correlates with the age of the patient.
For example, if the arrow is below the smallest ear, this indicates that the
sound level recorded is that which would be expected from a small ear
canal. You would expect this if you were testing a baby.
Individual ear canals vary considerably in size, so the indication of canal
size can only be used as an approximate guide to probe fit.