MATERIALS AND METHODS: A cross-sectional study was conducted among 127 randomly selected participants among marine technicians working on RMN vessels stationed at the Lumut Naval Base, Perak, Malaysia. The research instruments were questionnaires that contained information about sociodemographic, socioeconomic, occupational characteristics, and lifestyle behaviours, followed by a pure tone audiometric (PTA) assessment. Diagnosis of NIHL was made when the hearing threshold was ≥25 dB at 3 kHz to 6 kHz, with a recovery at 8 kHz on PTA.
RESULTS: The participants' median age was 32 years (interquartile range=27-37 years). The prevalence of occupational NIHL was 29.9% (95% CI=22.1-38.7). Factors associated with occupational NIHL on unadjusted regression analysis include age >30 years (OR=2.56, p=0.0185), middle household income (OR=2.76, p=0.0227), military rank especially the warrant officer (OR=7.12, p=0.0038), and length of service ≥15 years (OR=2.40, p=0.0246). After adjusting for ethnicity, smoking status, types of vessels, and participation in noise-related leisure activities, middle household income (OR=3.15, 95% CI=1.29- 7.87, p=0.0121) and warrant officer (OR=4.38, 95% CI=1.08- 20.52, p=0.0384) remained as significant predictors for occupational NIHL in this population.
CONCLUSION: In this study, the marine technicians working on board the RMN vessels had a higher prevalence of occupational NIHL compared to the prevalence among other MAF personnel as well as the global data. In addition, the probabilities of having occupational NIHL were significantly higher for middle-income technicians and those who ranked as warrant officers. These findings highlight the need for routine audiometric assessment and adoption of hearing conservation initiatives for individuals at high risk within this occupational cohort.