Prosodic features which cue back-channel responses in English and Japanese

Back-channel feedback, responses such as uh-uh from a listener, is a pervasive feature of conversation. It has long been thought that the production of back-channel feedback depends to a large extent on the actions of the other conversation partner, not just on the volition of the one who produces them. In particular, prosodic cues from the speaker have long been thought to play a role, but have so far eluded identification. We have earlier suggested that an important prosodic cue involved, in both English and Japanese, is a region of low pitch late in an utterance (Ward, 1996). This paper discusses issues in the definition of back-channel feedback, presents evidence for our claim, surveys other factors which elicit or inhibit back-channel responses, and mentions a few related phenomena and theoretical issues.