Elizabeth A. Hohne
Peter W. Jusczyk
Dept. of Psychol., Park Hall, SUNY at Buffalo, Buffalo, NY 14260
The role of allophonic constraints in speech perception was studied with 2-month olds and adults. English word and nonword stimuli were selected to have the same phonemic content, but different allophonic structure. In particular, some of the stimuli contained an allophone of the phoneme category /t/ that is used in signaling a boundary between two words (e.g., the /t/ in ``night rate''), whereas others contained an allophone appropriate to the middle of a word (e.g., the /t/ in ``nitrate''). Two-month old infants discriminated allophones corresponding to different word and nonword boundary locations. When vowel duration and other prosodic variables surrounding the allophones were equated, infants continued to discriminate them. These results suggest that the basis for discrimination is not simply prosodic in nature. The adult data, measured by a same/different discrimination task, differed from the infant data in the patterning of responses. There is some indication the adult data can be explained in terms of lexical effects. [Work supported by NICHD.]