Comparative Study of Evoked Otoacoustic Emissions in Offshore and Onshore Seafaring Workers

Abstract

Purpose: To evaluate the cochlear function of offshore and onshore seafaring workers of a naval company in the city of Rio de Janeiro and to estimate the degree of association between occupational exposure to noise and/or chemical substances and alteration in cochlear function. Methods: This study evaluated seafaring workers aged 20 to 49, of both genders, without auditory symptoms, divided into two groups: the Offshore Group, operating in the high seas with occupational exposure; and the Onshore Group, operating in offices without occupational exposure. Exams were performed to evaluate cochlear function, including transient evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE). Results: The TEOAE and DPOAE responses were on average lower in the Offshore Group, for all frequencies analyzed. The proportion of failures observed was also higher in the exposure group (Offshore), for general response and specific frequency, mainly for the frequencies of 4 kHz for TEOAE and 6 kHz for DPOAE. Conclusion: The results suggest that exposure to noise and/or chemical substances can contribute to alterations in cochlear function in seafarers even without manifesting auditory symptoms.