Occupational noise exposure and asymmetric hearing loss: Results from the HUNT population study in Norway

Occupational noise exposure and asymmetric hearing loss: Results from the HUNT population study in Norway:

Abstract

Background

A large population study with adequate data on confounders is required to determine whether asymmetric hearing loss (AHL) is associated with occupational noise exposure.

Methods

We performed a cross‐sectional population study in Norway (the Health Investigation in Nord‐Trøndelag: HUNT) with 24 183 participants, using pure‐tone audiometry and questionnaires. AHL was defined as a difference in hearing threshold between the right and left ears of greater than or equal to 15 dB for the pure‐tone average of 0.5 to 2 or 3 to 6 kHz.

Results

The mean age of the participants was 53 years (range, 19‐99); 53% were women. The prevalence of AHL in this general Norwegian population was 6% for the 0.5 to 2 kHz range and 15% for 3 to 6 kHz. In unadjusted regression models, subjects reporting prolonged occupational noise exposure to high‐level noise sources (N = 1652) had a higher risk of AHL at 3 to 6 kHz than those reporting no prior exposure (odds ratio [OR], 1.98; 95% confidence interval [CI], 1.75‐2.25). After adjustment for age and sex, OR was 1.08; (95% CI, 0.95‐1.24). After additional adjustment for head trauma, ear infections, blasting or shooting (all associated with AHL), smoking, and diabetes, OR was 1.00 (95% CI, 0.87‐1.16). No association between occupational noise and right‐ear hearing threshold advantage (left‐right ear difference) was observed after adjustment for confounders.

Conclusion

Our study suggests that AHL is relatively common in the general population, especially at the high‐frequency range in men and elderly subjects. Our study showed no relation between occupational noise exposure and AHL after confounder adjustment.