Setting The Averaging Time; Setting The Pass Snr Level; Setting The Number Of Frequencies For Pass - Interacoustics OtoRead Instructions For Use Manual

OtoRead™ Instructions for Use - US

3.11.6.3 Setting the averaging time

3.11.6.4 Setting the PASS SNR level

3.11.6.5 Setting the number of frequencies for PASS

The Averaging Time can be changed to one of five settings. The
Averaging Time will have a significant impact on the time required to
perform the test and on the signal-to-noise ratio (SNR). A 4 second
average would produce a test in about 4 seconds. A 32 second
average would produce a test in about 32 seconds. This timing is
independent of the probe check process. The possible settings for the
Averaging Time are as follows:
4, 8, 16, 32 or 64 seconds.
The instrument will automatically stop the test when the pass criterion
is met prior to the averaging time. Press the CHANGE key to select
an option and the NEXT key to exit.
In order to provide a PASS/REFER determination for each test, the
PASS SNR must be set. This number refers to the number of decibels
that the TEOAE signal must be above the noise to be considered a
PASS at that frequency. The limits for the PASS SNR are 3 dB to 10
dB. Pressing the LEFT or RIGHT arrow keys will increase or
decrease the requirement. This requirement is used in combination
with the number of frequencies (discussed below) to determine an
overall PASS/REFER for each test.
Press the CHANGE key to select an option and the
exit.
The number of frequencies for determining a PASS can be set from 0
to 6. If the setting is on 0, then no indication of PASS/REFER will be
made. This setting is used in conjunction with the PASS SNR to set
the criteria for the overall test PASS/REFER indication. For example, if
the PASS SNR is set to 4 dB and the number of frequencies for PASS
is set to 3 then the test must contain at least 3 frequencies where the
emission is at least 4 dB above the noise to indicate a PASS.
Press the CHANGE key to select an option and the
exit.
Diagnostic protocols display the SNR graph with light-green bars.
Once the 'Number of Frequencies for PASS' is set above zero, green
bars are displayed to identify this setting.
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