The protective effect of wearing hearing protection devices in noise-induced hearing loss and its potential influencing factors in the Chinese adult population.

BACKGROUND

Noise is a threat to human auditory system, hearing protection devices (HPDs) are widely used to prevent noise-induced hearing loss (NIHL). However, the role of wearing HPDs on NIHL and the complex relationship between them are still unclear. This study aims to explore such relationship and identify the associated influencing pathways. Providing the important targets for hearing health interventions.

METHODS

We tested audiometry and Personal Attenuation Ratings (PARs) in 862 participants, recording HPDs usage and fitting actions. Furthermore, an intervention, the comfort survey and the insertion depth measuring of foam earplugs were conducted with 455 participants. Using structural equation models to assess the association among these variables.

RESULTS

There were 18.1 % of participants who wore HPDs had NIHL in our study, and their baseline PARs were lower (p < 0.001). Then we found proper fitting actions and continuous use of HPDs led to higher PARs, with "roll" and "pull" being crucial for foam earplugs. In addition, baseline PARs (OR = 0.783; 95 % Cl: 0.644, 0.953) and HPDs wearing frequency (OR = 0.131; 95 % Cl: 0.079, 0.218) were the protective factors of NIHL. Moreover, both proper fitting actions (β = 0.237; 95 % Cl, 0.070, 0.404) and continuous wearing foam earplugs (β = 0.018; 95 % Cl: 0.010, 0.025) could moderate NIHL through baseline PARs, and they also had indirect effect on NIHL. HPDs wearing comfort and insertion depth could mediate the link between wearing HPDs and baseline PARs. The mediation effect of insertion depth on baseline PARs accounted for 35.5 %.

CONCLUSIONS

Our study found that people who wore HPDs improperly in noisy environments had a risk of suffering from NIHL. Highlighting the important role of proper fitting actions and continuously wearing HPDs in improving PARs and preventing NIHL, especially roll and pull actions for foam earplugs. Proposing that the insertion depth might be an auxiliary indicator to help screen workers that need to be focused on for identification and intervention.