The temporal effect in a notched-noise masker for normal-hearing and hearing-impaired listeners

Abstract

This is another in a series of studies on the relationship between the temporal effect (or overshoot) and the cochlear active process. The temporal effect refers to the change in threshold for a short-duration tone as it is delayed from the onset of a longer-duration masker. In a previous study, the temporal effect was measured as a function of signal level in a broadband masker, for listeners with normal hearing and listeners with varying degrees of cochlear hearing loss. When analyzed in terms of cochlear input–output functions, the results were consistent with a decrease in gain at the signal frequency during the course of the masker, as well as a decrease in gain with hearing impairment. In the present study, the temporal effect was measured for a 10-ms, high-frequency signal in a masker with a symmetric notch (relative frequency of 0.3) about the signal frequency, for listeners with normal hearing and cochlear hearing loss. This condition is of interest because the thresholds may reflect the effects of suppression as well as excitatory masking. The relationship between the degree of hearing impairment and the growth of masker level with signal level will be analyzed. [Work supported by the Kinley Trust.]