Noise-Induced Hearing Loss
Also written as: NIHL — Noise-Induced Hearing Loss
Permanent or temporary hearing loss resulting from prolonged or sudden exposure to high-intensity sound, characterised by a notch in hearing sensitivity at 4000 Hz.
Full Definition
Noise-induced hearing loss (NIHL) is a form of acquired sensorineural hearing loss caused by damage to the outer hair cells of the cochlea following excessive sound exposure. It may be permanent (permanent threshold shift, PTS) or temporary (temporary threshold shift, TTS) depending on the intensity and duration of exposure. The audiometric hallmark is a characteristic notch at 4000 Hz, with partial recovery at 8000 Hz. NIHL is a significant occupational health and public health concern and is the focus of industrial audiometry programs. In rehabilitation contexts, individuals with NIHL frequently present with disproportionately poor speech understanding in noise relative to their pure-tone thresholds. Editors should hyphenate the compound modifier 'noise-induced' when it precedes the noun 'hearing loss'.
Usage
Usage note: Always hyphenate 'noise-induced' when used as a compound modifier. Abbreviate as NIHL after first-use expansion. Do not confuse with acoustic trauma, which refers specifically to sudden-onset noise exposure.
In Context
- "The 4000 Hz notch on the audiogram, combined with an occupational history in heavy industry, was consistent with noise-induced hearing loss." — Audiological assessment report
- "Noise-induced hearing loss is largely preventable through the use of appropriate hearing protection in high-noise workplaces." — Occupational health report