Word segmentation of American English /s/ in semi‐spontaneous speech.

Abstract

To comprehend spoken language, listeners need to find words from a continuous stream of speech sounds. Little work has explored whether there are reliable acoustic cues to word boundaries in conversational speech, which is highly reduced and under‐articulated, potentially creating ambiguities at word boundaries. Segmentation may be even more difficult when the same segment repeats at a word boundary, ending the preceding word and beginning the following word (e.g., gas station). Segmentation in this environment was investigated by examining the production and perception of fricative /s/ in semi‐spontaneous speech. Twenty talkers produced sentences containing ambiguous two‐word sequences with /s/ between the two words. All sequences are interpretable in three ways (e.g., grow snails, gross snails, and gross nails) depending on how the frication is segmented. Acoustic analyses of the production data examined whether there are acoustic cues distinguishing the three versions of the ambiguous sequences. Listening experiments using the talkers’ productions as stimuli evaluated the degree of ambiguity in the tokens and identified acoustic cues that listeners use to segment the two words. Results will be discussed in the context of theories of speech perception and word segmentation.