INTRODUCTION: The otoacoustic emission test is useful in monitoring hearing changes not yet detectable in pure-tone audiometry, as well as in monitoring cochlear damage caused by exposure to noise. OBJECTIVE: To evaluate distortion product otoacoustic emissions in normal-hearing workers exposed to different occupational noise doses. MATERIALS AND METHOD: This is a cohort prospective study performed in metalworking industries, in which normal-hearing workers were assessed by being divided into three different groups: GI not exposed, GII sporadically exposed and GIII often exposed to occupational noise. RESULTS: Otoacoustic emission alterations were found in groups II and III bilaterally. Both in the amplitude and in the signal/noise ratio it was observed that as higher was the frequency, worse were the results of GII and GIII (p > 0.001), and the greater the exposure dose is, the lower the averages found in otoacoustic emission. CONCLUSION: The otoacoustic emissions are worse in the exposed groups compared to the unexposed group and the greater are the noise dose, worse are the results.
INTRODUCTION: The otoacoustic emission test is useful in monitoring hearing changes not yet detectable in pure-tone audiometry, as well as in monitoring cochlear damage caused by exposure to noise. OBJECTIVE: To evaluate distortion product otoacoustic emissions in normal-hearing workers exposed to different occupational noise doses. MATERIALS AND METHOD: This is a cohort prospective study performed in metalworking industries, in which normal-hearing workers were assessed by being divided into three different groups: GI not exposed, GII sporadically exposed and GIII often exposed to occupational noise. RESULTS: Otoacoustic emission alterations were found in groups II and III bilaterally. Both in the amplitude and in the signal/noise ratio it was observed that as higher was the frequency, worse were the results of GII and GIII (p > 0.001), and the greater the exposure dose is, the lower the averages found in otoacoustic emission. CONCLUSION: The otoacoustic emissions are worse in the exposed groups compared to the unexposed group and the greater are the noise dose, worse are the results.