One
of the noteworthy developments in the field
of Otolaryngology and Audiology is the advances
made in electrophysiology
of hearing. Several sophisticated tests
have evolved, making diagnosis of deafness
in the early years of life reliable and
safe. These are essentially non-invasive
investigations aimed at recording electrophysiological
responses of hearing. The tests include
Oto Acoustic Emissions (OAE) which
helps in quick screening of hearing,
Brain Stem Evoked Response Audiometry (BERA)
and Auditory Steady State Responses (ASSR)
which are sophisticated tools for assessing
responses from the brainstem, Electrocochleography
(ECochG) for recording electrical
potentials from the cochlea (inner ear)
and Electrically evoked Auditory
Brainstem Responses (EABR), another
important investigative modality for assessment
of hearing and nerve function after cochlear
implantation.
Promontory Stimulation Test
is a minimally invasive investigation wherein
electrical stimulation is applied to the
cochlea and subjective responses are assessed.
This is a useful test to assess hearing
in older children and adults where integrity
of nerve of hearing is in doubt. Responses
after cochlear implantation are assessed
by another special test called Neural
Response Telemetry (NRT). Thus
MERF has one of the best electrophysiological
laboratories in the country dedicated to
the assessment of hearing in hearing challenged
individuals.
|
