Beyond the Phoneme : A Juncture - Accent Model of Spoken Language

Phonemic models of spoken language are incapable of accommodating the patterns of pronunciation variation observed in spontaneous speech (as exemplified by a corpus of American English telephone dialogues, a.k.a. SWITCHBOARD). Variation in pronunciation with respect to segmental identity and duration can be accounted for in terms of a juncture-accent model, in which position of the segment within the syllable (i.e., onset, nucleus, coda), in tandem with knowledge of the associated stress-accent pattern, is used to interpret the inherently ambiguous phonetic information contained in the acoustic signal. Many properties of pronunciation variation can be accounted for in terms of such a model, including: (1) the prevalence of coda deletion, (2) the mutability of vocalic identity and (3) the relative stability of syllable onsets. The melding of phonetic and prosodic features within the syllable provides for efficient and reliable linguistic information coding.