User guide
BABYS
C
REEN
ECH001XN121-A4 – 07/2022
36
Chapter 4. Otoacoustic emission (TEOAE and DP-gram)
4.5 DP-gram
A progression bar informs you of the state of progress of a point. When the progression bar stops, the system updates
the point corresponding to the frequency being tested. This graph contains several kind of information :
1.
The green curve represents the power of the distortion product in dB at the various selected frequencies.
2.
The index given in white above a point is the power of the distortion product.
3.
The vertical white figures indicate the test frequency for each points.
4.
The red curve represents the average noise level.
The rejection indicator light notifies you when the rejection threshold is reached. If 40 successive rejections are de-
tected, the current point is rejected and the "
Rejection
" information appears on the screen. This phenomenon indicates
that the acoustic noise is too high. There can be several causes for this:
1.
The patient noise is too high. When the patient is more relaxed, measurement will start again automatically.
If the phenomenon persists, it means that the rejection threshold has been calibrated too low. Exit from the
measurement by clicking on "
Stop
" then restart a new measurement.
2.
The probe is incorrectly positioned. It is possible that the probe moves during measurement, in particular if
you are running postural tests. In this case, click on "
Stop
", replace the probe (paragraph
5.2.2
) and make
another measurement.
3.
The ambient noise is too high. The intrinsic noise in the room where you are making the measurement must
not exceed 60 dB.
The "
Stop
" button stops the measurement. Once the data acquisition is over, the curve is reconstructed. You then
have the choice of saving the data by clicking on "
Save
" or deleting it by exiting the window using the back cross.
the device switches to the next frequency when the validation conditions are reached or after having reached the
maximum test duration. After having tested all the selected frequencies, the device stops the measurement and indicates
whether the test is valid or not conclusive, depending on the number of frequencies at which the distortion product (DP)
was recorded.
At the end of the measurement, a popup shows if the test is valid or not.
End of a valid test
Nest measurement
Rejection level setting
Rejection indicator
Frequency in Hz
Progress bar
Noise level
Signal level in dB SPL
Current measurement
