How word onsets drive lexical access and segmentation: evidence from acoustics, phonology and processing

We argue that the beginnings of words are perceptual "islands of reliability" in connected speech, and that their perceptual and temporal properties allow them to drive critical aspects of spoken word recognition including lexical segmentation. This argument rests on three generalizations derived from research in speech science, phonology, and psycholinguistics. We suggest that word onsets differ from other parts of words in that: they offer more robust and redundant acoustic evidence about phonetic features; they are generally protected from phonological assimilation, neutralization and deletion and therefore show less lawful variation in surface realization; and they may activate lexical representations which facilitate word perception and thus diminish listeners' dependence on veridical acoustic phonetic processing of other portions of words. These properties of word onsets allow them to drive lexical segmentation by facilitating the recognition of items that begin with clear onsets. The implications of these findings for several models of lexical segmentation and spoken word recognition are discussed.