Occupational hearing disturbances associated with prolonged exposure to noise

Abstract

Objective: to identify hearing disturbances and analyze their relationship with occupational noise exposure among road-crew workers from a Municipal Decentralized Autonomous Government in Napo province, Ecuador. Method: observational, cross-sectional, descriptive and correlational study. The source population comprised 55 workers; after inclusion, exclusion and participation criteria were applied, 52 were analyzed. Pure-tone audiometry, calibrated sound-level measurements, review of previous records, and a structured questionnaire covering sociodemographic characteristics, occupational history, exposure, personal protective equipment use and relevant medical history were used. Results: all participants were men; 88% were exposed to noise for 5–8 hours per workday and 77% had accumulated more than 10 years of exposure. Sensorineural hearing loss was identified in 54%, acoustic trauma in 13%, conductive hearing loss in 10%, and hearing within normal parameters in 23%. Overall, 44.23% combined sensorineural hearing loss with exposure classified as high. The reported chi-square test was χ² = 1.46, df = 2, with p ≈ 0.48; therefore, no statistically significant evidence of association was obtained for the analyzed categories. Conclusion: the high frequency of audiometric abnormalities, together with prolonged exposure and inconsistent hearing-protection use among part of the workforce, supports strengthening hearing conservation programs. The cross-sectional design does not allow individual causal attribution to noise and cannot exclude the role of age, seniority and co-exposures.