An acoustic model of normal speech prosody

Abstract

Investigations of the mechanisms underlying durational effects have shown that the displacements and velocities of articulator movement for the same acoustic-phonetic segments are variable. Kinematic measures reveal more extreme displacements and increased velocity in stressed syllables as compared to weakly stressed syllables [Cohen et al., J. Acoust. Soc. Am. 98, 2894(A) (1995)], except for those in phrase-final position. To further our understanding of the acoustic consequences of prosodic variations, six normal speakers read sentences containing the syllable [pap] in response to a series of questions. Pairwise comparisons of the prosodic conditions showed statistically significant differences for four prosodic contrasts. For three of the four contrast, the speakers showed longer syllable durations and higher formant and f0 frequency values for stressed syllables. In the phrase-final accented versus non-phrase-final accented contrast, however, the phrase-final accented syllables, although showing longer syllable duration, displayed lower frequency values for F1, F2, and f0. These data suggest a model in which time emerges as a function of articulatory events rather than a determiner of those events.