Articulatory Timing and the Prosodic Interpretation of Syllable Duration

Abstract A number of different prosodic effects (e. g. intonation-phrase-final position, the presence of stress or accent) increase syllable duration, as conventionally measured by the spacing of abrupt energy transitions in the acoustic signal. However, different prosodic contrasts may have different influences on syllable-internal articulatory organization. The present study examined the time course of vowel-related opening and closing mandibular gestures in four different prosodic contexts. For some prosodic effects, such as intonation-phrase-final lengthening, longer acoustic durations were associated with a disproportionate lengthening of the latter part of the vocalic gesture. By contrast, the presence of nuclear stress was associated with a more even distribution of lengthening throughout the syllable. These results suggest that the rhythmic effects of different prosodic contrasts cannot be adequately modelled in terms of millisecond values or durational ratios for acoustic segments. It is proposed that a suitable phonological representation of the rhythms of stress and phrasing might describe them as the time course of a syllable’s phonetic sonority.