Comparing Intensity Elicited Maximum Reflex Amplitude between Noise Induced Hearing Loss & Acoustic Trauma at 1 kHz, Contra laterally, and Investigate Relationship between Amplitude and Hearing Impair

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.- 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 didnt produce at a significant linear correlation with subject's age and ear canal volume in both groups.3- The intensity elicited maximum reflex amplitude in NIHL group wasnt 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. Acoustic reflex amplitude is reduced for subjects with NIHL compared with acoustic trauma subjects.