Effect of onset asymmetry upon the perceived onset of a CV during dichotic presentation.

Data were gathered from four well-practiced subjects in a 2AFC paradigm which was subject driven, and allowed as many repeats of the stimulus pair as the subject requested prior to making his response. The stimuli consisted of the six stop-consonants followed by the vowel /a/. These natural speech CV's have served as stimuli in numerous dichotic speech perception studies. The results indicated that when the stimuli were separated by no more than 15 msec, the subjects could be divided into two homogeneous groups. One group was able to reliably determine a parallel pair of perceptual onset functions (one for each ear) which were of moderate slope and were separated by approximately 13 msec. The other group of subjects showed a reversal of the ear asymmetry and their perceptual onset functions had a zero slope. The results will be discussed in terms of its relevance to the temporal variables involved in dichotic CV experiments. [Supported by National Institutes of Health, USPHS Grant No. NS 11647-03.] [ABSTRACT FROM AUTHOR]