INTRODUCTION: Exposure to continuous or impulse noise may lead to high sound pressure-induced hearing loss (HSPIHL) or to acoustic trauma in soldiers. The importance of auditory evaluation by means of evoked otoacoustic emissions (EOAE) has been demonstrated in the detection of subtle changes in cochlear function still unidentified in threshold tone audiometry in subjects exposed to noise. OBJECTIVE: To study distortion product otoacoustic emissions (DPOAEs) before and after exposure to impulse noise in soldiers of the Brazilian Army. Materials and METHODS: This was an analytical, observational, longitudinal, and prospective study. Auditory evaluation was performed by means of DPOAEs in 60 soldiers before and after exposure to impulse noise, of whom 30 were reevaluated immediately after exposure and 30 were reevaluated 24 h after exposure. RESULTS: The statistical analysis revealed that both groups reevaluated after exposure to impulse noise showed decreases in amplitudes in comparison with the tests before exposure. As for the signal-to-noise ratio, there was a significant difference at frequencies of 6 and 8 kHz and there was a significant association between tinnitus complaints and the group reevaluated immediately after exposure to noise. CONCLUSION: The DPOAE test proved sensitive to subtle shifts after exposure to impulse noise, both with regard to the amplitude criterion and with regard to the signal-to-noise ratio, even 24 h after exposure. This demonstrated the applicability of the DPOAE test for monitoring the hearing of soldiers exposed to impulse noise.
