Sudden Sensorineural Hearing Loss Caused by Noise Exposure to Intense Sound

Kim, Kyoo Sang; Kim, Jinsook; Park, Keehyun

Abstract

Sudden deafness may be defined as a sensorineural hearing loss that develope over a period of hours or a few days. The severity of the hearing loss may vary from mild to total loss of perception of the most intense sound. The loss of hearing may be permanent, or the hearing may spontaneously return to normal or near normal. Proposed explanations for sudden idiopathic sensorineural loss revolve primarily around viral or vascular etiologies. In addition to noise-induced deafness, which can be divided into a slowly progressive deafness caused by prolonged intense noise exposure and acute acoustic trauma caused by a single exposure to very intense sound. 45- and 52-year-old healthy male smokers with no previous otologic history, noted the acute loss of hearing with tinnitus in his right ear during his unusual intense noise exposed activities. There were no other associated symptoms of dizziness or visual change. After several days without improvement, they presented to the department of otolaryngology. Physical examination, neurologic evaluation, and otorhinolaryngologic examination were essentially within normal limits except for the hearing loss on the right ear. An audiogram revealed a severe primarily sensorineural sensitivity loss on the right. Routine laboratory studies were within normal limits. Two patients denied previous barotrauma, atypical or unusual drug usage, and unusual physical exertion or strain. We observed evidence of cochlear abnormality. The presence of cochlear dysfunction is supported by acoustic reflex threshold and auditory brain-stem response. These findings strengthened the probability of an acoustic trauma origin for the sudden sensorineural hearing loss.