Are eyebrow movements linked to voice variations and turn-taking in dialogue? An experimental investigation.

Following our work on the relationship between eyebrow movements and the fundamental frequency of the voice, this article presents the results of a study on this phenomenon, and also on the temporal location of rapid eyebrow movements with respect to speaking turns during dialogue. We used an automatic movement-acquisition system coupled with the simultaneous, synchronized recording of the vocal production. This procedure permits an objective analysis of eyebrow movements in relation to the vocal production. The data obtained showed that the speakers' rapid eyebrow movements were associated both with turn-taking (occurring right before or right after speaking turn onset) and with changes in the fundamental frequency. These findings suggest that rapid eyebrow movements are mainly linked to motivation and the intention to communicate, and may also act as a focus marker in speech.