Coarticulatory information in natural speech stimuli is crucial for infant recognition of syllable sequences

Abstract

Recent research has determined that coarticulatory information in speech provides important cues to early word segmentation. This experiment investigates whether 7-month-old infants’ ability to recognize a string requires the presence of appropriate coarticulatory information in the speech familiarization stream. Following familiarization to a string of CV syllables, infants were tested to determine if sequences that co-occurred in the familiarization string were preferred over those in which the syllables did not appear adjacently during familiarization. Further, the test phase was conducted so that the items had either appropriate or inappropriate coarticulation information. The results indicate that infants tested on items with appropriate coarticulation listened significantly longer to strings that had appeared during familiarization than to the appropriately coarticulated control strings that never occurred together during familiarization. Interestingly, when presented with inappropriate coarticulation test items, infants showed no preference for previously familiarized strings over the non-co-occurring syllable strings. We conclude that infants are sensitive to coarticulation in recognizing sequences in a speech stream. Furthermore, coarticulatory cues, in combination with other cues to segmentation, greatly enhance recognition of syllable sequences. These results suggest that coarticulation plays an important role in early word segmentation. [Work supported by NIH Grants DC-03172 and SSHRC 752-98-0283.]