Noise-induced hearing loss
Noise-induced hearing loss is a preventable sensorineural hearing loss from cochlear hair-cell injury, either sudden after a single very loud blast (acute acoustic trauma) or gradual from cumulative occupational or recreational exposure (chronic noise-induced hearing loss), with high-frequency loss first and no restorative drug therapy once established.
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What this article covers
- Overview
A preventable sensorineural hearing loss from noise exposure: injury to the cochlear hair cells caused by sound energy, occurring in two patterns that share the same injured structure but differ in onset and cause.
- Epidemiology
A major contributor to the overall hearing-loss burden: hearing loss overall affects an estimated 50% of adults aged 60 to 69 years in the United States to a degree that impairs day-to-day…
- Risk factors
Chronic occupational or recreational noise exposure: the dominant risk factor for the gradual, bilateral, cumulative form.
- Pathophysiology
Direct injury to the stereociliated hair cells of the organ of Corti: noise energy damages these cells, which do not regenerate, producing a permanent sensorineural deficit.
- Clinical features
Bilateral, gradual, high-frequency hearing loss in the chronic form: patients with cumulative occupational or recreational exposure notice difficulty in the high-frequency range first, often before…
- Differential diagnosis
Vestibular schwannoma (acoustic neuroma): most dangerous mimic; unilateral, progressive sensorineural hearing loss with tinnitus and no exposure history, unlike the bilateral or exposure-linked…
- Diagnosis
This is a clinical diagnosis: a compatible noise-exposure history plus audiometric evidence of a sensorineural, high-frequency-predominant hearing loss, after excluding other causes: no imaging or…
- Management
First, stop or reduce further noise exposure immediately: remove the patient from the causative occupational task or recreational activity; this is the single most effective step to prevent…
- Complications
Permanent sensorineural hearing loss: the hair-cell injury does not regenerate, so continued or repeated noise exposure produces cumulative, irreversible threshold shift.
- Prognosis
Established sensorineural loss does not recover with medical therapy: the affected frequencies are permanently impaired once injured, whether from a single acute blast or cumulative chronic exposure.
- Prevention
Remove or reduce the source of noise exposure as the primary preventive action: the only measure that stops further hair-cell injury, since this is an exposure-dependent, dose-related injury, not one a preventive drug treats.
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