ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

4aSPb7. Infant dependence on acoustic cue redundancy: Discrimination of the word-final voicing contrast.

Margret A. Orme

Linda Polka

School of Commun. Sci. and Disord., McGill Univ., 1266 Pine Ave. West, Montreal, PQ H3G 1A8, Canada

Discrimination of a word-final stop consonant voicing contrast, /bid/--/bit/, by adults and infants at two ages (6--8 and 10--12 months) was investigated in a category-change conditioned headturn procedure across three stimulus conditions: full cue (FC), burst and closure cues neutralized (BCCN), and vowel duration neutralized (VDN). Adults performed at ceiling levels for all three conditions. No infant age differences were observed. However, there was some evidence that infants benefitted from the presence of redundant acoustic cues (FC>BCCN, but FC(not greater than)VDN). Infants performed significantly better with the VDN stimuli indicating that final release burst information is more salient to infants than vowel duration differences for this /bid/--/bit/ contrast. This result differs from findings of prior research on adult and infant perception of such contrasts which showed a prominent use of the preceding vowel duration cue. This finding suggests that vowel duration becomes useful as a cue to final stop voicing with linguistic sophistication. [Work supported by NSERC.]