Estimation of cochlear response times using lateralization of frequency-mismatched tones

Behavioral and objective estimates of cochlear response times (CRTs) and traveling-wave (TW) velocity were compared for three normal-hearing listeners. Differences between frequency-specific CRTs were estimated via lateralization of pulsed tones that were interaurally mismatched in frequency, similar to a paradigm proposed by Zerlin [(1969). J. Acoust. Soc. Am. 46, 1011-1015]. In addition, derived-band auditory brainstem responses were obtained as a function of derived-band center frequency. The latencies extracted from these responses served as objective estimates of CRTs. Estimates of TW velocity were calculated from the obtained CRTs. The correspondence between behavioral and objective estimates of CRT and TW velocity was examined. For frequencies up to 1.5 kHz, the behavioral method yielded reproducible results, which were consistent with the objective estimates. For higher frequencies, CRT differences could not be estimated with the behavioral method due to limitations of the lateralization paradigm. The method might be useful for studying the spatiotemporal cochlear response pattern in human listeners.