Effects of age and hearing loss on stream segregation based on interaural time differences.

The effect of interaural time differences (ITDs) on obligatory stream segregation for successive tone bursts was investigated for older listeners with normal hearing (ONH) and hearing loss (OHL), by measuring the threshold for detecting a rhythmic irregularity in an otherwise isochronous sequence of interleaved "A" and "B" tones. The A and B tones had equal but opposite ITDs from 0 to 0.5 ms. For some of the ONH listeners, the threshold increased with increasing ITD, but no OHL listener showed an effect of ITD. It is concluded that hearing loss reduces the potency of ITDs in inducing obligatory stream segregation.