Operating Instructions
15
5 Understanding the Test Results
5.1 Understanding the OAE Results Display
During OAE testing the results will appear on the screen as the test progresses. The display shows a
graph with up to 12 columns. Each f2 frequency (DPOAEs) or frequency band (TEOAEs) is indicated by
one column. The number of columns shown will vary depending on the number of frequencies being
tested with the selected protocol. The test frequency is shown along the horizontal axis at the bottom
of the display. Three different OAE viewing options are described below:
DP/TE-Gram
The
DP/TE-Gram graph
displays the absolute values of the signal
(emission) as a block plotted at the intersection point of the test
frequency (Hz) along the horizontal axis and the amplitude (dB SPL)
along the vertical axis.
Note: Boys Town normative data may optionally be shown on the
display for qualifying DPOAE measurements when the DP/TE-Gram
graph is used as shown in the display to the left. See Setup section
8.10 for more information regarding Boys Town norms.
A bright solid block indicates that the SNR is at least 6 dB for DPOAE
and 4 dB for TEOAE. A hashed block indicates that the SNR is less
than these specified values. Examples are shown in the display to the
left.
This allows the user to judge the quality of the measurement and the
possible influence of noise while still viewing the absolute emission
values on a simple to read display.
Value Graph
The
Value graph
displays the absolute values of the signal (emission)
and noise floor. The noise is represented by an open bar. The signal is
a represented by a solid bar when it meets the pass criteria and as a
dashed bar when it fails to meet the pass criteria for the protocol.
When viewing the value graph the user can immediately see if noise
was a contributing factor in obtaining a Refer.
For example on the test result shown to the left we can see that the
measurement at 2 kHz (the bar farthest to the right) is completely
obscured by noise (no measurable signal). At 3 kHz there is some noise
in the measurement, but the measured signal at that frequency meets
or exceeds the pass criteria. At 4 kHz the signal emerging above the
noise does not meet the pass criteria. At 5 kHz there is no noise in the
measurement. This is an example of a test that should be repeated
after an attempt is made to reduce noise (environmental or patient)
and obtain a better probe fit.
Summary of Contents for Ero Scan Pro
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