Occupational noise exposure and tinnitus: the HUNT Study

Abstract

Objective We aimed to assess the association between occupational noise exposure and tinnitus. Further, to assess whether the association depends on hearing status. Design In this cross-sectional study, tinnitus (>1 h daily) was regressed on job exposure matrix (JEM)-based or self-reported occupational noise exposure, adjusted for confounders. Study sample The 14,945 participants (42% men, 20–59 years) attended a population-based study in Norway (HUNT4, 2017-2019). Results JEM-based noise exposure, assessed as equivalent continuous sound level normalised to 8-h working days (LEX 8 h), over the working career or as minimum 5 years ≥85 dB) was not associated with tinnitus. Years of exposure ≥80 dB (minimum one) was not associated with tinnitus. Self-reported high noise exposure (>15 h weekly ≥5 years) was associated with tinnitus overall and among persons with elevated hearing thresholds (prevalence ratio (PR) 1.3, 1.0–1.7), however not statistically significantly among persons with normal thresholds (PR 1.1, 0.8–1.5). Conclusions Our large study showed no association between JEM-based noise exposure and tinnitus. This may to some extent reflect successful use of hearing protection. High self-reported noise exposure was associated with tinnitus, but not among normal hearing persons. This supports that noise-induced tinnitus to a large extent depends on audiometric hearing loss.