Independence of frequency channels in auditory temporal gap detection

The ability of listeners to detect a temporal gap in a 1600-Hz-wide noiseba nd (target) was studied as a function of the absence and presence of concur rent stimulation by a second 1600-Hz-wide noiseband (distractor) with a non overlapping spectrum. Gap detection thresholds for single noisebands center ed on 1.0, 2.0, 4.0, and 5.0 kHz were in the range from 4 to 6 ms, and were comparable to those described in previous studies. Gap thresholds for the same target noisebands were only modestly improved by the presence of a syn chronously gated gap in a second frequency band. Gap thresholds were unaffe cted by the presence of a continuous distracter that was either proximate o r remote from the target frequency band. Gap thresholds for the target nois eband were elevated if the distracter noiseband also contained a gap which "roved" in time in temporal proximity to the target gap. This effect was mo st marked in inexperienced listeners. Between-channel gap thresholds, obtai ned casing leading and trailing markers that differed in frequency, were hi gh in all listeners, again consistent with previous findings. The data are discussed in terms of the levels of the auditory perceptual processing stre am at which the listener can voluntarily access auditory events in distinct frequency channels. (C) 2000 Acoustical Society of America. [S0001-4966(00 )00412-4].