Abstract

The current real-time vocal tract MRI study examines the articulatory encoding of prosodic boundary, prominence and their interaction through kinematic analysis of penultimate and final lengthening near an intonational phrase (IP) boundary in Setswana. One hypothesis is that penultimate lengthening represents a specific case of final lengthening initiated on the IP-penultimate position. Alternatively, penultimate lengthening and final lengthening may result from the interaction between phrase-level prominence and boundary events. Our results reveal two phases of lengthening in the IP-penultimate and IP-final positions. Displacement and peak velocity are also greater IP-finally than IP-medially, but boundary-related increase in displacement and peak velocity only shows a single progressive trend approaching the final IP boundary, with no IP-penultimate alterations comparable to durational patterns. Additionally, there is some evidence for greater duration, displacement and peak velocity of initial consonant gestures on word-penultimate syllables than on word-final ones regardless of utterance positions, indicating a possible word-penultimate prominence effect. These findings suggest that penultimate and final lengthening in Setswana are better understood as the interaction between disparate prominence and boundary events. The results are interpreted according to a prosodic gestural approach that posits the coordination of a phrasal-prominence-encoding μgesture and a boundary-encoding π gesture.

Date

2026

Authors

Yubin Zhang, Xuan Shi, Kevin Huang, Prakash Kumar, Kevin Lee, Boitumelo Moshoete, Keneilwe Matlhaku, Dani Byrd, Louis Goldstein, Krishna Nayak, Shrikanth Narayanan

Conference

Proc. SpeechProsody 2026

Pages

53-57