Personal earplug fit testing identifies below-target attenuation in nearly two-thirds of military aviation personnel: a retrospective analysis of results before and after individualized instruction.

BACKGROUND

Noise-induced hearing loss (NIHL) remains an important occupational health problem, especially in high-intensity noise work settings. Although disposable foam earplugs (DFE) are widely used, the protection they provide depends on how well they are fitted. We examined initial earplug attenuation in military aviation personnel, the change observed after individualized on-site instruction and repeat fitting among participants initially below target, and the association between previous instruction and baseline attenuation.

METHODS

This retrospective, single-center observational study analyzed routinely collected occupational-health fit-testing data from 183 military aviation personnel evaluated between 2020 and 2022. Mean age was 22.84 ± 6.23 years, and 91.3% were male. Earplug attenuation was measured using the 3M E-A-Rfit Dual-Ear Validation System. Participants with mean binaural attenuation below 20 dB received individualized on-site instruction and repeated the fitting procedure.

RESULTS

During initial fitting, 118 participants (64.5%) did not achieve the 20 dB target. In this group, mean binaural attenuation rose from 14.47 to 22.57 dB after instruction and repeat fitting, an improvement of 8.10 dB (p < 0.001). Participants who reported having received previous earplug-use instruction also had higher baseline attenuation than those without previous instruction (19.47 vs. 16.52 dB; p = 0.002).

CONCLUSION

Quantitative fit testing identified inadequate initial attenuation in nearly two-thirds of the personnel assessed. Brief individualized instruction followed by repeat fitting was associated with a substantial improvement in attenuation among those initially below target. Incorporating personal fit testing and targeted instruction into occupational hearing-conservation programs may improve protection against NIHL.