The International Tinnitus Journal

Otoacoustic emissions in normal-hearing workers exposed to different noise doses

Author(s): Marlene Escher Boger; Andr? Luiz Lopes Sampaio; Carlos Augusto Costa Pires de Oliveira

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.

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