Analysis of inter- and intra-speaker variability of head motions during spoken dialogue

Head motions naturally occur in synchrony with speech and may carry paralinguistic information, such as intentions, attitudes and emotions, in dialogue communication. With the aim of verifying the relationship between head motions and the linguistic and paralinguistic functions carried by speech, analyses were conducted on motion-captured data of several speakers during natural dialogues. The analysis results firstly confirmed the trends of our previous work, showing that regardless the speaker, nods frequently occur during speech utterances, not only for expressing dialogue acts such as agreement and affirmation, but also appearing at the last syllable of the phrases, in strong phrase boundaries, especially when the speaker is confidently talking, or expressing interest to the interlocutor’s talk. Inter-speaker variability indicated that the frequency of head motions may vary according to the speaker’s age or status, while intraspeaker variability indicated that the frequency of head motions also differ depending on the inter-personal relationship with the interlocutor.