Detection of interaural time differences for clicks and tone pips: effects of interaural signal disparity

The ability to detect small interaural time differences (delta t) was determined in 4 subjects using clicks or long tone pips of various interaural signal disparities which are expressed as the extent of interaural spectral overlaps. The interaural signal disparity was varied by changing (a) the interaural pulse duration difference (delta d) for clicks, or (b) the interaural carrier frequency difference (delta f) for tone pips. In either case, the sensitivity to delta t was maximal under diotic presentations and declined with delta d or delta f. The overall sensitivity to delta t was remarkably higher for clicks than for long tone pips. The results indicate that both (a) the extent of binaural spectral overlaps and (b) the structure of acoustic stimuli are important in detecting small interaural time differences of binaural sounds.