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| The Auditory Brainstem Response (ABR)
measures the electrical activity of the hearing nerve pathway
from the inner ear to the brain. In this test, a clicking sound
is presented to one ear at a time. The electrical activity of
this signal is recorded by electrodes. The average response is
displayed as a waveform that contains peaks and troughs, which
correspond to various points along the hearing nerve. The time
between these peaks is measured and compared to normal data.
A delay in response might indicate an abnormality on or near
the hearing or balance nerve. The ABR is also helpful
in the diagnosis of multiple sclerosis (demyelinating diseases
of the brain), tumors (acoustic neuroma) of the eighth cranial
nerve (hearing and balance nerve) and strokes (vascular lesions)
of the brainstem. ABR testing can serve as both a screening
tool for hearing and a diagnostic assessment of the severity
of loss in infants or in individuals unable to perform a conventional
hearing test. Infants may require sedation for this test. ABR
is also used in the operating room to monitor auditory function
during surgery. |
American Academy of Otolaryngology. 2000. Academy of Otolaryngology.
20. Sept. 2001 <http://www.entnet.org>.
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