Transient evoked otoacoustic emissions in occupational medicine as an auditory screening test for employment

TEOAEs are considered a valuable test for specific evaluation of the inner ear function and can be used as a screening method for an objective diagnosis of cochlear damage. The aim of this study was the evaluation of TEOAEs as a diagnostic tool for adult male subjects undergoing medical selection for recruitment in the Italian Air Force (IAF). The analysis was performed with ILO88 System on 30 normal and 83 hearing-impaired subjects. Only cochlear hearing losses were considered and categorized in three classes: unilateral (UHL), bilateral (BHL), high frequencies (HFHL: cochlear damage only at 6 and/or 8 kHz). TEOAE intensity, reproducibility and spectrum were the main parameters investigated. A qualitative comparison between the responses obtained in the two ears of the same subject was also performed. Moreover, TEOAE spectra and Pure Tone Audiometry (PTA) data were compared. Significant differences between the normal and the affected ear in UHLs were found, while no variations between the two ears were observed in BHLs and HFHLs. A high correlation between TEOAE spectrum and PTA was reported in normals and UHLs. The global test sensitivity was high in UHLs (94%) and BHLs (83%), while specificity was 85.0% in the normal sample. Although significant limitations reduce their efficiency, TEOAEs can be regarded as a useful complementary test to standard PTA for audiological selective purposes.