Hearing threshold shift measured by otoacoustic emissions after shooting noise exposure in soldiers using hearing protectors.

Abstract

The aim of the study was to assess the influence of short-term impulse noise to temporary threshold shift in soldiers using hearing protectors. The study included 80 subjects with correct tympanic membrane and thresholds measured by pure-tone audiometry less than 20 dB. There were two groups: 40 soldiers protected during shooting and 40 young males who didn't shoot. TEOAE were performed by ILO 292 Echoport Otodynamics device 3 to 5 minutes before shooting and 2 minutes and 1, 2, and 3 hours after shooting. Short-term exposure to impulse noise generated by five gunshots from the rifle kbk AKMS hasn't induced temporary threshold shift of hearing for chosen frequencies in soldiers using hearing protectors. Spectral analysis for chosen frequencies revealed that measurement reproducibility, stimuli level, and probe stability appeared to be comparable and repeatable. Our results show that the use of hearing protectors safeguarded against impulse noise. The use of earmuffs is strongly recommended because they seem to sufficiently attenuate shooting noise.