Pitch similarity in the vicinity of backchannels

Dynamic modeling of spoken dialogue seeks to capture how interlocutors change their speech over the course of a conversation. Much work has focused on how speakers adapt or entrain to different aspects of one another’s speaking style. In this paper we focus on local aspects of this adaptation. We investigate the relationship between backchannels and the interlocutor utterances that precede them with respect to pitch. We demonstrate that the pitch of backchannels is more similar to the immediately preceding utterance than nonbackchannels. This inter-speaker pitch relationship captures the same distinctions as more cumbersome intra-speaker relations, and supports the intuition that, in terms of pitch, such similarity may be one of the mechanisms by which backchannels are rendered ’unobtrusive’.