Temporal effects with multiple-burst multitone masking.

Abstract

Previous work has shown that the detection threshold for a tone-burst target presented simultaneously with a randomized multitone masker that is not affected by increasing the number of identical target-plus-masker bursts. However, when the masker burst is repeated, but the target tone is presented only in alternate bursts, masked detection thresholds may be reduced significantly [Kidd et al., (1994). J. Acoust. Soc. Am. 95(6), 3475–3480]. In the present study, similar conditions were tested, but the masker-alone bursts were presented either ipsilateral or contralateral to the target-plus-masker bursts. In addition, the detectability of a single target burst was measured when the target-plus-masker burst was either preceded or followed by masker-alone bursts. As is typical with random multitone maskers, there were large threshold differences between listeners, but ipsilateral presentation of the alternate masker-alone bursts provided greater benefit than contralateral presentation. Furthermore, some listeners showed no improvement of single-burst detection thresholds with either pre- or postcursors, while others showed a sizable improvement that was similar for both pre- and postcursors. Discussion will focus on possible mechanisms underlying these temporal informational masking effects.