Here we have mentioned the case of  a Caucasian man affected with human immunodeficiency virus during blood injection in a heart surjury.He demonstrated vertigo, dissequilibrium and neurological problems secondry to his disease 4 years later. Auditory and vestibular system disfunction became obvious based on the neurological examinations. optokinetic nystagmus, ataxia in addition to lack of response by caloric stimulation was attained in electronystagmographic examination.absolute latencies and interpeak intervals were prolonged in the auditory brain-stem responses(ABR).abnormal low scores were obtained in SSI test bilaterally.organic brain lesion and severe anxiety have been diagnised during psychological examination.Human immunodeficiency virus was detected in brain, cerebellum and brainstem cells by means of autopsia.meanwhile the pathologic changes were cosistent with neuro-otological findings.

Method and Materials :this cross sectional descriptive and analytic survey was done at Golestan navy hospital in Tehran, between June 1998 and March 1999 on total of 69 male subject (104 ears, ) 50 acoustic trauma & 54 noise induced H.L) between 20 to 40 ears old.
Results:1- The mean acoustic reflex threshold at 1 kHz showed there is no significant difference between two groups.
2- The intensity elicited maximum reflex amplitude at 1 kHz didn&apost produce at a significant linear correlation with subject&aposs age and ear canal volume in both groups.
3- The intensity elicited maximum reflex amplitude in NIHL group wasn&apost shown a significant correlation with ear compliance and gradient.
4- The mean Intensity (SPL) elicited maximum reflex amplitude in NIHL group was more than mean intensity (SPL) in acoustic trauma group.
5- The mean intensity (SL) elicited maximum reflex amplitude in NIHL group was More than mean intensity (SL) in acoustic trauma group.
Conclusion: Acoustic reflex amplitude is reduced for subjects with NIHL compared with acoustic trauma subjects.