High resolution system for improved transient-evoked otoacoustic emission acquisition

Transient-evoked otoacoustic emissions (TEOAE) are generated by the cochlea in response to clicks. They are obtained by averaging post-onset acoustic responses which are composed of the stimulus-related meatal response (MR) and the TEOAEs. TEOAEs are typically below normal hearing thresholds and are obstructed by the MR, which is several orders of magnitude higher. For click stimuli, MRs typically last about 5 ms and obstruct the early latency emissions. TEOAEs become compressively nonlinear as the MR increases, and this property is commonly exploited by obtaining a derived nonlinear response (DNLR) which reduces the MR artifact. In this study we report the development of a high-resolution system which linearly acquires both MRs and TEOAEs. Results show that the duration of the artifact can be reduced, making the high frequency content of TEOAEs observable.