Charles A. Harsin
Robert J. Porter, Jr.
Dept. of Psychol., Univ. of New Orleans, Lakefront, New Orleans, LA 70148
To investigate how syllabic differences might be conveyed by the manifestations of articulator gestures in the absolute and relative timing of acoustic cues, speech signals corresponding to the V+C+V sequence /ipi/ were created. The durations of various acoustic cues were independently manipulated, and subjects were asked to judge whether particular signals had the structure /i#pi/ or /ip#i/. Subjects were also asked to discriminate among the same signals. A clear, ``categorical'' relationship was found between bursts' relative temporal positions in the intervocalic interval and syllabic categorization. On the other hand, discrimination measures revealed sensitivity to small absolute differences in segment durations regardless of judged syllable type. Thus, a comparison of syllable judgment and discrimination results suggests that both absolute and relative temporal cues are available for perceptual decisions but that relative cues are selected for syllable judgments, perhaps because they map more directly onto the relative timing of articulatory gestures. [This research was supported in part by University of New Orleans Chancellor's Fellowship.]