Clinical Characteristics of Acoustic Trauma Caused by Rifle Gunshot Noise

Abstract

Background and Objectives：One of the major occupational hazards of working in the military service is being subjected to intense impulse noise, hence acoustic trauma. Acute acoustic trauma is a preventable disease, but the effective treatment modality has not been established yet. Acute acoustic traumas caused by exposure to rifle gunshot noise are common in young Korean males in the military service because of conscription policy. Through the analysis of the clinical presentation of acoustic traumas caused by rifle gunshot noise, we suggest effective preventive modalities. Subjects and Method：165 soldiers who had otologic symptoms after performing regular rifle gunshot exercise without any hearing protective measures were analyzed. They all had been tested with K2 rifle. History taking, physical examination, pure-tone audiometry, and impedence audiometry, temporal MRI, and Newmann’s tinnitus inventory questionnaire survey were performed. Results：Most common and annoying symptom was tinnitus. The average outcome of postexposure air conduction thresholds were 22.3dB HL in the affected ear and 11.8dB HL in the unaffected ear. There was no correlation between severity of tinnitus and severity of hearing loss. Asymmetry of hearing loss related to head position during gunshot was not found. This may be due to the fact that during the mass gunshot training, each patient can be influenced by the gunshot noise of the adjacent gunner’s shooting. Conclusion：Widening the distance between firing lanes and providing bilateral hearing protective devices against acoustic trauma must be taken into serious consideration. (Korean J Otorhinolaryngol-Head Neck Surg 2008;51:699-704)