PERCEPTUAL SEGREGATION OF A HARMONIC FROM A VOWEL BY INTERAURAL TIME DIFFERENCE IN CONJUNCTION WITH MISTUNING AND ONSET ASYNCHRONY

The two experiments reported here examine how an inter-aural time diff erence (ITD) interacts with two other cues, mistuning and onset asynch rony, in reducing the contribution of a single frequency component to the perception of a vowel's identity. Previous experiments have shown that although ITD is generally rather ineffective at segregating a sim ultaneous harmonic frequency component from a vowel. it can produce so me segregation when listeners have already been exposed to the isolate d segregated component. A difference in ITD increases segregation over all in experiment 1 where the to-be-segregated component can also have a different onset time from the remainder of the vowel, and experimen t 2 shows a similar result when the to-be-segregated component is mist uned. However, segregation by ITD is present just as strongly on trial s when there is neither mistuning nor a difference in onset-time as on trials where these additional cues are present. Segregation on trials when there is neither mistuning nor a difference in onset-time is how ever larger in the present experiment which mixed all conditions toget her than in similar trials in an earlier experiment that had a blocked design [C. J. Darwin and R. W. Hukin, J. Acoust. Sec. Am. 102, 2316-2 324 (1997)]. The results show that segregation by ITD increases when o ther more potent cues are present in the experiment. (C) 1998 Acoustic al Society of America. [S0001-4966(98)00302-6].