Auditory neuropathy spectrum
disorder (ANSD) is a retrocochlear disorder in which cochlear functioning is
normal but the transmission in the auditory neural pathway is affected. The present study reports of neural fatigue seen in subjective and objective tests of adaption in a 19 year old adult with ANSD. He had bilateral mild
sensorineural hearing loss with otoacoustic emissions present and absent
auditory brainstem response.
Immittance evaluation showed elevated acoustic
reflexes at 500 Hz and 1000 Hz in both ipsilateral and contralateral
stimulation. Reflex decay test was administered at 500 Hz and 1000 Hz which showed positive reflex decay with contralateral stimulation. Olsen and
Noffsinger tone decay test and supra-threshold adaptation test showed positive
tone decay at 500 Hz, 1000 Hz and 2000 Hz in both ears.