Noise-Induced Hearing Loss
Also written as: NIHL — Noise-Induced Hearing Loss
Sensorineural hearing loss resulting from exposure to hazardous sound levels, characteristically presenting as a notched audiometric configuration centred at 4000 Hz.
Full Definition
Noise-Induced Hearing Loss (NIHL) arises from damage to cochlear outer hair cells caused by prolonged or acute exposure to high-intensity sound. The hallmark audiometric signature is a threshold notch most pronounced at 4000 Hz (occasionally 3000 or 6000 Hz), with relative recovery at 8000 Hz. NIHL is a major focus of occupational health documentation, and editors working in industrial audiology or medicolegal reports should ensure the term is consistently hyphenated ('noise-induced') and that causal language is used carefully—audiometric findings alone cannot prove causation without supporting occupational history. The condition is permanent and progressive with continued exposure; editors should flag language that implies reversibility.
Usage
Usage note: Always hyphenate 'noise-induced' as a compound modifier. Distinguish acute 'acoustic trauma' from chronic NIHL in editorial review; do not use them interchangeably.
In Context
- "The 4000 Hz notch observed bilaterally was consistent with noise-induced hearing loss related to the claimant's 20-year employment in the foundry." — Medicolegal audiology report
- "Editors should ensure 'noise-induced' is always hyphenated and that causal claims are supported by occupational history data within the report." — Editorial style guidance