장병들의 사격에 의한 소음성 난청

Abstract

Background and Objectives：Noise induced hearing loss (NIHL) is a preventive disease and yet the effective treatment modalityhas not been established. Acute acoustic traumas caused by an exposure to gunshot noise are common in young Koreanmales in the military service. Considering the significant lack of awareness on this serious issue as well as the absence of properprotection gears, an in-depth analysis is desperately needed. Subjects and Method：3,650 soldiers performed a regular gunshotexercise without any hearing protective measures. Out of 3,650 soldiers, 8 patients with hearing impairment after the regular gunfirevisited aeromedical squadron. They were all right-handed males：7 had been tested with K-2 rifle and 1 had been tested withK-5 revolver. History taking, physical examination, pure-tone audiometry, and impedence audiometry were performed. In thenext round of gunshot practice, all soldiers performed gunfire with unilateral hearing protection. Results：The average outcomeof postexposure air conduction thresholds were 6.5 dB in the right ear and 33.1 dB in left ear. After medical treatment, hearingimpairment was much improved；however, tinnitus was not diminished. In the next round of gunshot practice, the supplementof unilateral earplug protection proved its effectiveness on acoustic trauma caused by gunfire noise. Conclusion：Asymmetryof hearing loss was related to head position during gunfire. Unilateral hearing protection device was enough to protect hearingfrom acoustic trauma caused by gunshot. At the same time, it can effectively prevent a potential firearm accident that can becaused by trainees mishearing the instruction of firearm instructor if both earplugs are worn. Thus, providing unilateral earplugprotection against acoustic trauma must be taken into serious consideration. (Korean J Otolaryngol 2006;49:887-91)