Hearing Screening Systems (Technical Manual)
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is just under the information panel. Besides, the top part contains a status line and the
bottom one has the active menu line.
The information panel contains two linear scales: the one is for the displaying of the
acoustic meatus volume (“volume”) and the other one is for the noise level displaying
(“noise”). If the noise level or the volume exceeds the admissible bound, the
corresponding scale becomes red, if it is does not, it is of the green color. When the
OAE probe is fitted correctly, both scales are in the green area. If during a short-term
check the device detects that the OAE probe is fitted bad, the “Check probe fitting”
message will appear above the stimulus shape curve. In this case it is necessary to
press the “Close” function key, reinstall the OAE probe and start the test again.
Fig. 18. Seal control mode. DPOAE test.
Note: control passing of the OAE probe fitting does not guarantee its correct setting because
the device can not follow the situation when the probe tip is fit against the wall of the ear canal
or when the canal is closed, for example, by the impacted cerumen.
If the device considers that the OAE probe is fitted correctly, it will switch to the mode
of the telephones bandpass flatness calibration. In the left part of the window the
bandpass flatness of the one telephone and then the other one will appear. After that
the device will switch to the stimulus intensity tuning.
After the stimulus intensity tuning, the device switches to DPOAE registration mode.
The screen view in this mode is given in the Fig. 19. The DP (distortion product) dia-
gram window will appear in the left part of the screen. The levels of the received OAE
on each frequency will display as filled circles of the red color for the right ear and of
the blue color for the left one. The grey filled triangles show the noise level. The list of
the frequencies will appear on the information panel. During the testing the “PASS”
(
) or “REFER” (
) symbol will appear opposite each frequency. If the consider-
able noise or nonstable OAE probe position prevents from the results achieving, the
symbol “?” will appear. Besides the information panel contains the “N” linear scale to
