The role of interaural time difference (ITD) in perceptual grouping and selective attention was explored in three experiments. Experiment 1 showed that listeners can use small differences in ITD between two sentences to say which of two, short, constant, target words was part of the attended sentence, in the absence of talker or fundamental frequency differences. Experiments 2 and 3 showed that listeners do not explicitly track components that share a common ITD. Their inability to segregate a harmonic from a target vowel by a difference in ITD was not substantially changed by the vowel being placed in a sentence context, where the sentence shared the same ITD as the rest of the vowel. The results indicate that, in following a particular auditory sound source over time, listeners attend to perceived auditory objects at particular azimuthal positions rather than attending explicitly to those frequency components that share a common ITD
