The influence of co-speech gesture presence on the timing of F0 peaks in a tonal language

Abstract

The timing of co-speech gestures has been shown to correlate with the location of pitch peaks in speech in several non-tonal languages. While little research has examined this relationship in tonal languages, existing work suggests that pitch peak timing does not show the same synchronous alignment with manual gesture timing. In this paper, we examine whether the presence of a gesture can have an influence on timing of pitch peaks in Medʉmba, a tonal Grassfields Bantu language. Manual gesture data were analyzed from spontaneous interview speech of six Medʉmba speakers. In line with prior findings on tonal languages, manual gesture apexes and pitch peaks did not align, and gesture-accompanied vowels were not realized with higher or more dynamic pitch profiles (though they were realized with longer duration and greater intensity; ps < .01). The findings did indicate, however, that f0 peaks—particularly for high, falling, and low tone syllables—were realized earlier in gesture-accompanied vowels than non gesture-accompanied vowels (p < .05). We interpret these findings in the context of an integrated model of speech and manual gesture in which tonal gestures and manual gestures are both crucially timed to vowels, but timed to occur sequentially with one another.