Otoacoustic emissions in a hearing conservation program: General applicability in longitudinal monitoring and the relation to changes in pure-tone thresholds

The hearing status of workers (N=233) in a priming office was assessed twice within seventeen months by pure-tone audiometry and otoacoustic emissions (OAEs) One of the questions was how a quality criterion of OAE-measurements based on a minimum signal-to-noise-ratio (SNR) would affect the applicability on the entire population Secondly. effects of noise exposure were investigated in overall changes in audiogram and OAE-measurements For TEOAEs (transient evoked OAEs) in the frequency band of 4 kHz, only 55% of the data points meet the SNR-inclusion criterion For DPOAEs (distortion product OAEs) around 6 kHz approximately 80% of the data points satisfy the criterion Thus OAEs have a limited applicability for monitoring the hearing status of this entire population Audiometry shows significant deteriorations at 6 and 8 kHz TEOAEs show a significant decline at all frequency bands (1-4 kHz). DPOAEs between 4 and 8 kHz and less pronounced between 1 and 2 kHz On group level. OAEs show a decline in a larger frequency region than the audiogram. suggesting an Increased sensitivity of OAEs compared to audiometry