2-MONTH-OLD INFANTS SENSITIVITY TO ALLOPHONIC DIFFERENCES

The present study investigated 8-month-olds' abilities to discriminate allophonic differences that are potentially useful in segmenting flue nt speech. Experiment I investigated infants' sensitivity to the kind of distinction that may signal the presence or absence of a word bound ary. When tested with the high-amplitude sucking procedure, infants di scriminated pairs of items, such as ''nitrate'' versus ''night rate'' and ''nikrate'' versus ''nike rate.'' By greatly reducing the potentia l contribution of prosodic differences to these contrasts, Experiment 2 evaluated whether the allophonic differences for /t/ and /r/ were su fficient for infants to distinguish the ''nitrate'' versus ''night rat e'' pair. Infants distinguished ''nitrate'' from a cross-spliced versi on of ''night rate,'' which differed only in the allophones for /t/ an d /r/ that it included. Thus, infants appear to possess one of the pre requisite capacities (i.e., the ability to discriminate allophonic dis tinctions) necessary to use allophonic information in segmenting fluen t speech.