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 Impairment

Abstract

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: 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;t produce at a significant linear correlation with subjects age and ear canal volume in both groups. 3- The intensity elicited maximum reflex amplitude in NIHL group wasn't 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