Dissecting rate of speech: The effect of phrase final lengthening on articulation rate.

Abstract

Articulation rate in a Mexican American community in Texas is examined in order to determine which social, cognitive, and linguistic factors influence the rate of speech. This research represents one facet of a larger inquiry into variation in temporal patterns in American English. Recent work has demonstrated the strong effect of utterance length on articulation rate—the (pause‐exclusive) measure of speech units, typically syllables, produced per unit of time—but utterance‐internal factors have been less examined. Here, particular attention is paid to the extent to which articulation rate may be a function of phrase‐final lengthening, i.e., is variation in articulation rate a spurious effect of variability in phrase‐final lengthening? The analysis of finely time‐aligned orthographic transcripts conducted here, coded for intonational and intermediate phrases, indicates that rates of speech for final feet are tightly correlated with rates for non‐final feet. Hence variation in articulation rate is not an artifact of the final feet. Non‐linguistic factors, such as speaker sex and age, are shown to differentiate articulation rates significantly, though individual variability is also substantial. Statistical models of utterance‐level‐based and within‐utterance articulation rate measures are compared and implications for studies of speech rate are discussed.