Introduction
The purpose of the Corti test system is to provide rapid measurement and
documentation of Distortion Product Otoacoustic Emissions (DPOAEs) or
Transient Evoked Otoacoustic Emissions (TEOAEs) at several frequencies.
How Does the Corti Device Work?
The system consists of the instrument,
probe, printer, single-use eartips
replaceable probe tubes and other
accessories. The Corti instrument
contains the hardware and software for
generating the test stimuli, measuring and
displaying the OAEs, and storing the
results until they are printed. The plastic
housing contains circuit boards that
provide the signal processing and display
the test results. The instrument also
contains a rechargeable lithium-ion
battery to power the device. The
instrument uses a liquid-crystal display
(LCD) and three light-emitting diodes
(LEDs) to provide a visual display of test
status to the operator. Four push buttons
located on the keypad of the device allow
the user to control testing and printing,
and to reset test protocols.
The Probe houses the speaker and
microphone which produce test stimuli
and measure the sound pressure level
(SPL) present in the sealed ear canal.
Interface of the instrument to the ear canal
is accomplished through disposable
eartips, which fit onto the probe tube. The
disposable eartips are color coded to
facilitate easy selection by size.
What are DPOAEs?
Distortion Product Otoacoustic Emissions (DPOAEs) are acoustic
signals that can be detected in the ear canal of a person with normal
outer hair cell function, subsequent to stimulation of the auditory
system with a pair of pure tones at frequencies f1 and f2. The resulting
emission of interest is the distortion product tone at the frequency
2f1-f2.
The Corti instrument generates a series of test tones, directs them into
the ear canal, and then measures the level of the DPOAE tone
generated by the cochlea. By using different test frequencies, the
User Interface
Buttons
Probe Connector
Micro-USB
Connector
Figure 1
Charge Status
Indicator
Display
Test Status
Indicators
