The phrasal organization in speech gestures and co-speech head and eyebrow beats

Non-referential, beat-like gestures that accompany speech are often recruited as coparticipants for marking prosodic structure, especially signaling prominence. Only few studies have examined the coordination between vocal tract and co-speech gestures in relation to phrasal boundaries. Our recent study with eight Korean speakers (5F, 3M) has revealed that co-speech manual beat gestures and speech are synchronous with both phrase-edge segment and tone gestures [Lee et al., JASA 152, A199 (2022)]. Building on this, the present study examines different gesticulators, namely, co-speech head and eyebrow movement using the same eight speakers. We specifically test how the spatiotemporal patterning of vocal tract actions and cooccurring body movements systematically varies at phrasal boundaries and under prominence. We hypothesize that co-speech head and eyebrow movement are also temporally coordinated with prosodic phrases in Korean. The movements of the lips, tongue, eyebrows, and head were point-tracked using EMA. Measurements taken included the duration of intervals from the timepoint of concurrent beat gesture onset and target to various phrasal landmarks. The results on inter-articulator organization of prosody will be discussed. [Work supported by NSF.]