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 presented simultaneously with a masker, either without or with preceding acoustic stimulation. Evidence suggests that this phenomenon is related to changes in gain in the cochlea due to the prior 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 place. 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 as well as growth of masking functions with and without prior acoustic stimulation 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 were analyzed in terms of changes in gain at the signal and suppressor place and show that gain is decreased at both places. Additionally, predictions using an auditory nerve model suggest that neural adaptation and the neural response to the masker may also be important.
Degree
Ph.D.
Advisors
Strickland, Purdue University.
Subject Area
Audiology
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