Transient evoked otoacoustic emissions in workers exposed to ocupational noise

Abstract

The objective of this study was to compare otoacoustic emissions of two groups of 80 individuals each, one of them exposed and the other, non-exposed to occupational noise. The inclusion criteria were: normal threshold hearing, normal results in the acoustic imittance test, noise exposure for at least one year for the exposed group. The individuals were matched by gender and age. Occupational and clinical records were investigated. The group exposed to occupational noise showed a higher prevalence of absence of transient evoked otoacoustic emissions at least in one ear: 68,75% compared to the non-exposed group (55,75%). Statistical analysis indicated a significant association between occupational noise exposure and absence of transient evoked emissions (x2 = 6,619, p = 0,01). The exposure to non-occupational noise can be responsible for the absence of responses to otoacoustic emissions among normal hearing individuals. The study discusses the role of otoacoustic emissions tests as an additional surveillance tool detecting early hearing losses among those with occupational noise exposure.