Abstract:

The auditory system does not appear to adopt an efficient wideband temporal analysis if the temporal event to be detected traverses frequency with concomitant spectral discontinuity across the temporal event. In order to determine whether spectral continuity across the temporal event is a prerequisite for wideband temporal analysis, a novel paradigm was implemented in which the temporal event to be detected was a gap in the modulator of a sinusoidal carrier (the carrier was present throughout the modulation gap). The two markers of the modulation gap could be carried either by the same carrier frequency or by different frequencies across the modulation gap. In the latter case, the multiple carrier frequencies were continuously present whether they were carrying the modulation or not. Modulation gap detection was measured for an 8-Hz modulator carried by multicomponent stimuli whose standard duration was 625 ms. For all listeners, modulation gap detection deteriorated when the modulation gap traversed carrier frequency relative to when it was carried by a single frequency. Results will be discussed in terms of the conditions necessary for wideband temporal analysis. [Work supported by NIH NIDCD R01-DC01507.]