Abstract
OBJECTIVE: To investigate the association between hearing loss and cognitive function in noise-exposed workers, to evaluate the predictive value of multimodal audiological and neurophysiological indicators, and to analyze the influence of covariates, including smoking, alcohol consumption, hypertension, and diabetes. METHODS: In this cross-sectional study, 170 noise-exposed workers with at least 6 months of exposure were enrolled from 2023 to 2025 using cluster sampling. Participants underwent pure-tone audiometry, tympanometry, otoacoustic emissions (OAEs), auditory brainstem response (ABR), and the Montreal Cognitive Assessment (MoCA). Data on demographics, smoking, alcohol consumption, hypertension, and diabetes were collected. Pearson correlation, multiple linear regression, hierarchical regression, and bootstrap mediation analysis were performed. RESULTS: The study included 170 participants, of whom 97.1% were male. The mean age was 46.9 ± 9.8 years, and the mean duration of noise exposure was 6.9 ± 5.7 years. The mean high-frequency hearing threshold was 54.9 ± 10.2 dB, and the mean MoCA score was 26.2 ± 2.1. Hearing thresholds and ABR wave V latency were both significantly negatively correlated with MoCA scores (p < 0.05). The absolute correlation coefficients ranged from 0.2 to 0.3, indicating weak to moderate correlations. Multiple regression analysis showed that age, exposure duration, and high-frequency hearing threshold were independent predictors of MoCA score (p < 0.05). This association remained stable after adjustment for smoking, alcohol consumption, hypertension, and diabetes. Mediation analysis revealed that hearing loss played a significant mediating role in the negative effect of occupational hazard exposure duration on cognitive function. Specifically, 47.6% of the total effect of exposure duration on cognitive function was mediated by high-frequency hearing loss. The observed correlation coefficients were modest (e.g., r ≈ -0.3), suggesting a small to moderate clinical effect size. Hypertension was also independently associated with lower MoCA scores (β = -0.120, p = 0.048). CONCLUSION: In this predominantly male cohort of noise-exposed workers, hearing loss was significantly associated with cognitive decline. This association was independent of age, exposure duration, and other health risk factors, including smoking, alcohol consumption, hypertension, and diabetes. These findings suggest a potential link between occupational hearing loss and cognitive function. However, because of the limitations of the cross-sectional design, causal relationships cannot be inferred. A multimodal assessment integrating audiological, neurophysiological, and health risk factors may provide a more systematic and objective reference for early identification, risk warning, and the development of comprehensive occupational health intervention strategies for cognitive decline in occupational populations.