Effects of impact noise on the hearing of military personnel

Shooting is an activity that exposes military personnel to noise impact, which may cause irreversible effects on hearing.ObjectiveTo evaluate impact noise on the hearing of military personnel that practice shooting.Study designA case-control retrospective study.Methods115 military personnel were enrolled; 65 had been exposed to impact noise and 50 were non-exposed. Firearm noise levels were evaluated, subjects answered a questionnaire and underwent threshold tonal audiometry and otoacoustic emissions testing.ResultsThe average noise level was 125dB(C). Most subjects (78%) believe that noise may cause hearing loss; nearly all (92.3%) used ear noise protectors while shooting, but most (32.3%) had never received guidance for using this equipment. There were significant differences between the two groups in relation to changes suggesting impact noise-induced hearing loss.ConclusionThe differences between groups show that noise-exposed military personnel are more likely to develop hearing loss. The goal of a hearing conservation program for this population should be to preserve hearing and educate these individuals about the importance of using hearing protection correctly.