Occurrence and Persistence of Tinnitus after Acute Acoustic Trauma by Gunshot

Lee, Yong Won

Abstract

BACKGROUND AND OBJECTIVES
Acute acoustic trauma (AAT) by gunshot can be the cause of hearing loss and tinnitus. Tinnitus after AAT frequently disappears with time. But the prognosis of this injury is very difficult to predict. This study tried to identify the factors influencing on tinnitus to occur and persist after AAT.
SUBJECTS AND METHOD
A group of 268 military subjects who get the gunshot training with K-2 rifle once after conscripted was asked to answer the questions: age, otologic history, number of firing, usage of earplugs, presence of tinnitus after gunshot and its characteristics, relapsed time after firing, Tinnitus Severity Index (TSI) questionnaire. Physical examination and pure tone audiometry were conducted to the subjects with existing tinnitus on the questionnaire.
RESULTS
95 patients (36.4%) experienced tinnitus immediate after gunshot among 261 subjects. It is obvious that wearing earplugs could prevent immediate tinnitus after AAT. There was statistical significance between tinnitus with earplug and without it (p=0.000). At the time of questionnaire, 27 (10.3%) were complaining of tinnitus. Among factors such as age, number of firing, wearing earplugs, severity of tinnitus and relapsed time after firing, only severity of tinnitus has the significant effect with the persistence of tinnitus (p=0.046).
CONCLUSION
Wearing earplugs can prevent tinnitus immediately after AAT, but does not seem to be the factor decreasing the prevalence of tinnitus. It was the only factor related to severity of tinnitus and to existing tinnitus.