Unimodal and Bimodal Backchannels in Conversational English

This paper presents differences in use of verbal ((oh) yeah, (mh)mh, okay . . . ) and visual backchannels (head nods, shakes, tilts), e.g. unimodal backchannels, as well as bimodal backchannels that combine a verbal token and a head movement in conversational English. We analyze the participants’ gaze-pattern before the production of a BC but also during and immediately after its delivery. We also analyze their placement regarding the main speaker’s turn and within the discourse topic. Lastly, we discuss their functions. Our findings reveal that each BC type shows a different picture from the other two both in terms of where they occur within the main speaker’s turn and what their functions are. We however do not confirm previous observations regarding the constraints on their occurrence within a discourse topic.