Dpoae; About The Dpoae Module; Brief Introduction To Dpoae - Interacoustics Eclipse Additional Information

Eclipse Additional Information

8 DPOAE

8.1

About the DPOAE module

The Eclipse DPOAE module is intended for use in the diagnostic audiologic evaluation and documentation of
ear disorders using Distortion Product Otoacoustic Emissions. The target population for Eclipse DPOAE in-
cludes all ages.
The Eclipse DPOAE module is designed to be used only by skilled personnel such as audiologists, ENT sur-
geons, doctors, hearing healthcare professionals or personnel with a similar level of education. The device
should not be used without the necessary knowledge and training to understand its use and how results
should be interpreted.
The Eclipse DPOAE module contains the following tests:
 DP-Gram
 DP-I/O Test
The DPOAE module is used to test the function of the outer hair cells. The DPOAE can be measured as an
I/O test or a DP gram. The DP-Gram tests are used to test the outer hair cell function at different frequencies
at a fixed intensity. The DP-Gram provides useful information regarding frequency specific regions of the
cochlea. The DP input/output tests are used to test the outer hair cell function at different intensities at a
fixed frequency.
Availability of these tests or specific settings within these tests on the hardware or in the software depend on
the license purchased.

8.1.1 Brief Introduction to DPOAE

The Otoacoustic Emission was first described in 1978 by Kemp, D. T. Since then it has gained clinical ac-
ceptance as a test of the cochlea, in particular outer hair cell function.
The emission is a sound generated within the cochlea either spontaneously or in response to acoustic stimu-
lation. In a normal ear, sound is transmitted to the cochlea via the stapes footplate. The travelling wave
mechanism is responsible for excitation of hair cells along the basilar membrane within the cochlea. The hair
cells are located at frequency specific places on the basilar membrane. The excitation of the hair cells will
depend on the frequency of the stimulus used. The excitation of hair cells starts an active mechanical ampli-
fication process within the cochlea. This active amplification from the outer hair cells also produces a side
product, an inverse travelling wave within the cochlea. This response can be recorded from the inner ear and
is known as an otoacoustic emission.
Distortion product otoacoustic emissions (DPOAEs) are elicited by two pure tones (f1 & f2). Due to the active
processes within the cochlea, a third tone, or distortion product, is produced at (2f1-f2). Typically several
pairs of tones are presented at particular frequencies in order to evaluate different frequency regions of the
cochlea. DPOAE measurements require two speakers and one microphone (these are incorporated in the
OAE probe used by both the TEOAE25 and DPOAE20 module).
Page 167