[The protective effects and influencing factors of hearing protection devices for noise-exposed workers in different...

Objective: To explore the current status of the protective effects of hearing protection devices worn by noise-exposed workers in different industries and its possible influencing factors. Methods: From October 2020 to December 2023, by using the method of convenient sampling, 3634 noise-exposed workers from 7 industries including the petrochemical industry, automotive manufacturing industry, plastic manufacturing industry, and metal manufacturing industry, were selected as the survey subjects. A questionnaire designed by the research group was adopted to investigate the usage of hearing protection devices (foam earplugs, preformed earplugs, and earmuffs) among workers. The personal attenuation rating (PAR) of workers wearing hearing protection devices was measured by using the 3M(TM) E-A-R fit(TM) binaural verification system. Three process tests were carried out, including baseline PAR, intervention PAR (training demonstration of correct wearing of hearing protection devices, replacement of appropriate hearing protection devices and other interventions), and follow-up PAR. The differences of PAR in each group were analyzed by non-parametric tests, and the generalized linear regression model was used to explore the factors that might affect the baseline PAR. Results: The M (Q(1), Q(3)) of the baseline PAR obtained by 3634 workers wearing hearing protection devices was 12 (2, 19) dB. There was a statistically significant difference in baseline PAR among the three types of hearing protection devices (H=336.39, P<0.001), and the baseline PAR of workers wearing foam earplugs and earmuffs were higher than that of preformed earplugs (P<0.05). There was a statistically significant difference in baseline PAR among workers in different industries (Z=359.73, P<0.001). Workers with college degree or above education level, wearing hearing protection devices for 10 to <30 years, foam earplugs and earmuffs, noise intensity≥85 dB (A), knowing the correct wearing method and evaluating the comfort of hearing protection devices had a higher baseline PAR (P<0.05). There were 1559 workers (42.9%) failed the baseline PAR test. After the intervention, the PAR of the workers increased from 1 (0, 6) dB at baseline to 18 (14, 22) dB after the intervention (P<0.001). The follow-up test found that the follow-up PAR of 328 workers was higher than the baseline PAR but lower than the intervention PAR (P<0.001) . Conclusion: The actual protective effect of the hearing protection devices worn by some workers exposed to noise is not good, mainly related to factors such as insufficient knowledge of wearing hearing protection devices among workers, exposure to high-intensity noise, and low educational level. Enterprises should enhance the training of workers on the correct wearing of hearing protection devices by means of hearing protection device fit test methods, select suitable hearing protection devices scientifically, and conduct regular follow-ups when necessary.