Transient otoacoustic emissions and frequency selectivity

Abstract

The relationship between transient evoked otoacoustic emissions (TEOAE) and frequency selectivity in the auditory system was examined. Three subjects with normal hearing sensitivity and TEOAE spectra with prominent peaks and valleys participated. Psychophysical tuning curves were measured at two pairs of frequencies: one where a robust emission occurs, and the other for an emission with a signal-to-noise ratio at least 6 dB SPL lower than the first. A forward masking paradigm with a 2AFC, 3 up – 1 down adaptive procedure was used to construct three point tuning curves. Quiet threshold for a given probe frequency was established first. The tip of the tuning curve was then obtained by determining the masker level for P(C)=79.1 with a probe at 10 dB SL. Finally, the Q—10 frequencies were acquired by adapting the frequency of the masker, which was set 10 dB above the tuning curve tip [Spetner and Olsho, 1990]. Preliminary results indicate that the Q—10 values for the tuning curves from the TEOAE peak frequencies are consistently greater than those of the tuning curves from valley frequencies. These results suggest that a relationship exists between frequency selectivity in the auditory system and the relative minima and maxima of TEOAE patterns. [Research supported by a grant from The Ohio State University College of Social and Behavioral Science.]