[Otoacoustic emission examinations in soldiers before and after shooting].

Firearms are a common source of impulse noise that may potentially damage hearing organ. The purpose of this study was evaluation of the click evoked otoacoustic emission (TEOAE) and distortion-product otoacoustic emission (DPOAE) before and after shooting and comparison with conventional pure tone audiometry. Standard pure tone audiometry, tympanometry, TEOAE and DPOAE were made before and 10-15 minutes after shooting. Ten male soldiers (20 ears) were exposed to impulse noise from automatic gunfire (15 single rounds of live ammunition). They did not use any earplugs. The reduction amplitude of the TEOAE after shooting was found especially for the frequency 3,4 kHz for the right ear and 1 and 2 kHz for the left ear. The DPOAE greatest reduction concerned frequency 2,5 and 4 kHz for the left ear. All our shooters were right-handed and probably the asymmetrical effect resulted from the shooting posture. Any differences existing between the audiometric threshold before and after shooting were not noticed. Clinical experience with OAE indicates that it may play a role as a screening method for the soldiers exposed to noise and as a tool for monitoring early changes in cochlea. Emissions seem to be more sensitive for monitoring early cochlear changes after shooting than pure tone audiometry.