Distortion-product otoacoustic emission fine structure as an indicator of combination-tone-mediated masking release

Abstract

During simultaneous masking, when the probe (fp) is higher in frequency than the masker (fm), the cubic difference tone (CDT; fcdt = 2fm-fp) can provide masking release. Given their shared origin, the 2f1-f2 distortion-product otoacoustic emission (DPOAE) may be a physiological correlate of CDT-mediated masking release [McFadden et al. (2012). J. Acoust. Soc. Am. 132, 968–983]. To test this hypothesis, masking release and DPOAEs were measured in normal-hearing listeners for 2 and 4 kHz probes. Probe threshold was measured in the presence of a masker (fp/fm = 1.2) and masker-suppressor pair. The suppressor was designed to mask detection of the CDT. Masking release was calculated as the change in masked-probe threshold resulting from presentation of the suppressor. DPOAEs were measured for an f2 (f2/f1 = 1.2) between 1.8 and 2 kHz (6-Hz intervals) and between 3.6 and 4.4 kHz (12-Hz intervals). Masking release was associated with DPOAE fine structure. Listeners without masking release lacked DPOAE fine struc...