High-frequency transient evoked otoacoustic emissions acquisition with auditory canal compensated clicks using swept-tone analysis

The meatus (auditory canal) plays a role in altering the waveform of incident sound, distorting time- and frequency-domain characteristics. Often in transient-evoked otoacoustic emission (TEOAE) recording protocols, a 75 mu s click is utilized to elicit a click-evoked response. TEOAEs are recorded by a probe microphone placed in the meatus and last for about 20 ms. Time-domain ringing in the meatal response (MR) creates a stimulus artifact that lasts up to 5+ ms, obscuring early-latency TEOAEs. This research is motivated by the need for a real-time, ear and probe placement dependent method for minimizing the magnitude and phase distortions of the meatus. The MR is first obtained using swept-tone analysis, from which a compensated stimulus is created. Usage of a compensated click from normally hearing adult subjects show an improvement to the flatness of the magnitude response and linearization of the phase response. Furthermore, a reduction in effective duration of the MR is found, attenuating the meatal artifact for click stimuli. The high frequency TEOAE content found in the early latencies of the response that is typically obscured by the MR artifact is revealed with the use of a compensated click.