The role of suppression in temporal masking effects

Abstract

The temporal effect refers to the change in signal-to-masker ratio at threshold for a short-duration tone as it is delayed from the onset of a longer-duration masker. Evidence suggests that this phenomenon is related to changes in gain in the cochlea due to acoustic stimulation by the masker. Research has suggested that for off-frequency maskers, the temporal effect is consistent with a decrease in suppression, which may depend on a decrease in gain at the suppressor frequency. Most previous studies have utilized simultaneous masking paradigms to measure the temporal effect. The present study used tonal maskers in a forward masking paradigm, and measured temporal masking curves to elucidate the role of suppression in temporal masking effects. A previous study had also showed that the pattern of the temporal effect with level depended not only on the degree of hearing loss at the signal frequency, but also on the degree of hearing loss above the signal frequency. The present study examined this further by using listeners with normal hearing as well as listeners with a notched cochlear hearing loss. Results will be analyzed in terms of changes in gain at signal and suppressor frequencies. [Work supported by Lions Club McKinney Outreach Award.]