Hearing Screening Systems (Technical Manual)
10
How Does Screening Systems Record TEOAE?
The
Neuro-Audio-Screen
and
Neuro-Audio-Screen/OAE
screening systems gener-
ate a series of clicks using a telephone, direct them into the ear canal, and then
average the response received by the microphone built in the probe recording OAE.
Owing to the use of the fast Fourier transform for the spectral analysis and the
bandpass filters, the devices provide an estimate of outer hair cell function over a
wide range of frequencies.
How Does Screening System Record DPOAE?
The
Neuro-Audio-Screen
and
Neuro-Audio-Screen/OAE
screening systems
generate a series of test tones using two telephones, direct them into the ear canal,
and then measure the level of the DPOAE tone generated by the cochlea by the
microphone built in the probe. By using different test frequencies, the devices provide
an estimate of outer hair cell function over a wide range of frequencies.
2.1.2. Auditory Brainstem Response and Its Recording
What is ABR?
Auditory brainstem response (ABR) is an electrical signal recorded from the
electrodes placed on the head of a patient with the normally functioning organs of
hearing including the auditory nerve and projection areas of the cerebral cortex. This
signal is the result of the auditory analyzer stimulation by the series of the auditory
pulses.
What Do ABR Test Results Tell Us?
As far as ABR is generated by the cochlea, the auditory nerve and the projection
areas of the cerebral cortex, we can safely say that the ABR presence indicates the
normal functioning of all the above mentioned auditory system parts and a patient
hears an acoustic signal directed to the ear canal.
How Does Neuro-Audio-Screen Screening System Record ABR?
The
Neuro-Audio-Screen
screening system generates a series of clicks using a
telephone, directs them into the ear canal, and then averages the electrical signal
received from the electrodes placed on a patient’s head. As a result ABR is obtained.
Owing to the high frequency of stimulus delivery (up to 93 Hz), the device can register
the so called steady-state potentials. These potentials differ in the high amplitude, are
easily and quickly separated, practically not influenced by the external
electromagnetic fields.
