105
Slope
This is the rate of growth of DPOAE with increase in L2. SLOPE has been
related to the quality of the cochlea. A low (shallow) SLOPE and a high
“dB at 80” value being indicative of good cochlear health.
Units: μPa/dB or dB/dB
dB at 80
This is a predicted level of DPOAE obtained by extrapolating the data to
L2=80dBSPL.
This value is a useful parameter to record for comparing the intensity of
DPOAE, at different frequencies, on different occasions and between
patients.
Units: dB SPL
Fit (R2)
A measure of the quality of the fit of the best fitting line to the data. A line
which passes through all the data points will have an R
2
of 1. A value of
R
2
close to 0 indicates that the line is a very poor fit to the data. A low R
2
value means that test results depending on the fit of the line to the data
(such as Thresh and Slope) are unreliable. R
2
is not displayed unless the
DPOAEs at three test levels are valid (according to criteria set in ‘Display
Logic’).
Line fit criteria
DP Growth results depend on there being a good fit (ie a linear relationship)
to the data. They are not reported if the fit of the data to the line is poor
or if insufficient data has been collected. Specifically, the display of line fit
data requires that:
• The fit quality measure r
2
>= 0.8
• 3 Test frequencies be valid (according to criteria set in ‘Display Logic’)
• The measured slope is equal to or greater than 0.1 uPa/dB
DPOAE test
Otoport OAE+ABR
User Manual for Advance and Screener
Summary of Contents for Otoport Advance
Page 296: ...CHAPTER THIRTY TWO Index 296...
