Otoport OAE+ABR
User Manual for Otoport DP+TE model
73
DPOAE test
8.2.6
Test condition information
When conditions are good for data collection
DP TEST
will be shown at the
top of the screen and progress indicators will move either side of the title to
show that a test is currently running. If test conditions are not optimum, a
highlighted message will appear, indicating the problem. (See section
7.2.3
Checkfit condition information
).
8.2.7
Minimum recordable signal level
Low level signals at the DPOAE frequency may not always be of cochlear
origin. At each frequency the Otoport assesses the minimum recordable
signal. At some higher frequencies (as listed in table below) and with
stimulus levels above 65dBSPL the minimum recordable signal level
increases and so a larger signal is required for a DPOAE to be recorded.
If the signal level is below the minimum recordable signal level the value
is disregarded and the Otoport shows a substitute ‘marker’ signal level of
-30dB instead.
Note that reaching the Minimum valid signal level indicates only that the
signal recorded is valid for processing, not that the DPOAE level that
frequency is normal or that it meets the signal to noise requirement set for
the test.
Below is a table of the minimum valid signal levels in dBSPL for a range of
frequency and stimulus levels.
Frequency (F2 kHz)
Level (L2) <5.2 5.6 5.9 6.1 6.4 6.7 7.0 7.3 7.6 8.0
65dBSPL
-10 -10 -10 -10 -10 -10 -10 -10 -10 -10
70dBSPL
-10 -10 -10 -7 -8 -10 -9 -8 -10 -10
75dBSPL
-10 -10 -2 -6 -7 -10 -8 -7 -7 -10