Perception of coarticulatory variation in Shona

In Shona, a Bantu language, anticipatory vowel-to-vowel coarticulation is very strong in some VCV sequences, such as /api/. Two experiments were conducted to test whether native listeners are sensitive to these coarticulatory effects. The stimuli were versions of /api/, /apa/, /upi/, /upa/ in which the first vowel had been cross spliced from original /_pi/, /_pa/, or /_pu/ environments. In experiment 1, the task was to press a button whenever the second vowel was /i/. Subjects' responses were fastest when the first vowel carded the appropriate coarticulatory information (i.e., when it derived from the original /_pi/ environment). In experiment 2, subjects responded whenever the first vowel was /a/; they were slowest when the /a/ came from original /api/. Thus coarticulatory shifts in vowel quality facilitate the processing of later occurring information while, at the same time, they make the vowel itself less prototypical. These results, together with similar ones obtained by others for English, illustrate listeners' perceptual sensitivity to subphonemic phonetic variation. [Work supported by NICHD.]