Proceedings of the Annual Meeting of the Cognitive Science Society

Infants face the difficult problem of segmenting continuous speech into words without the benefit of a fully developed lexicon. Several information sources in speech—prosody, semantic correlations, phonotactics, and so on—might help infants solve this problem. Research to date has focused on determining to which of these information sources infants might be sensitive, but little work has been done to determine the usefulness of each source. The computer simulations reported here are a first attempt to measure the usefulness of distributional and phonotactic information in adult- and children directed speech. The simulations hypothesize segmentations of speech into words; the best segmentation hypothesis is selected using the Minimum Description Length paradigm. Our results indicate that while there is some useful information in both phoneme distributions and phonotactic rules, the combination of both sources is most useful. Further, this combination of information sources is more useful for segmenting childdirected speech than adult-directed speech. The implications of these results for theories of lexical acquisition are discussed.