Backchannel Facts
What is a Backchannel?
Backchannels are feedback given while someone else is talking, to show interest, attention and/or a willingness to keep listening. Backchannels are typically short utterances such as uh-huh.
Here is a real example, also with audio:
H Is it like a party, like, ``rave'' type party? or like
C well, it's someone's house
H yeah
C there's going to be, I mean there's like, they're going to be spinning. So, in that sense, maybe, but it's just at someone's house, like
H yah-yeah
C it's in the middle of the night, that too, but.
Backchannels are also sometimes known as "response tokens," "reactive tokens," "minimal responses," and "continuers".
Why do People Backchannel?
Dialog includes not only the information that is being exchanged, but also the management of the communication and the expression of nuances of attitude and intention [7]. This is done sometimes with words, but more often with subtle uses of prosody, gesture, gaze, and backchannel utterances. This dimension of interaction helps make dialogs more enjoyable and more efficient.
What are the Most Common Backchannels?
Here are five of the most typical backchannels in a few languages.
American
English [5] Mexican
Spanish Japanese [5] Iraqi
Arabic French [10] German [1]
1 yeah si un aih oui ah (ach)
2 uh-huh si si ee nam ouais ja (ahja, aja)
3 hm ajá aa repetition humhum mhm
4 right mjm laughter mmm hum nein (ne)
5 okay laughter hai hmm ah okay
other languages
some less-common backchannels in English
Why Aren't These Words in Dictionaries?
Backchannels exhibit enormous fine phonetic variation. Alongside uh-huh, there are sounds like uh-hm, uhh-hm, un-hn, uh-huh-uh-huh, huhm, and so on. These are less words than they are dynamic creations, with each specific backchannel incorporating some exact sequence of sounds chosen to express some exact combination of nuances [6].
Does Backchannel Behavior Differ Among Languages?
One clear difference is in the frequency: backchannels are very common in Japanese, fairly common in English, Dutch, Arabic, and Korean, probably somewhat less common in German, and significantly less common in Chinese and Finnish [2,3,5,8]. (The Nativlang Aizuchi video illustrates some of this.) However this is also affected strongly by other factors, including the personalities of the speaker and listener, the context, and the culture [4].
When Should One Backchannel?
Obviously one can backchannel when the other person has the floor, but backchanneling just anytime can be rude. Listeners should in general give backchannel feedback at times when the other person seems to be welcoming it, and in many cases these times are marked by prosodic features of the speaker's utterances: these in effect are cues for feedback, although responding is generally optional.
For English, one such feature is a region of low pitch lasting 110 milliseconds or more (see diagram); about 700 milliseconds after this is a good time to produce a backchannel.
Different rules apply for other languages (link).
Arabic in particular is very different, although there's still a prosodic cue, as described in Al Bayyari's Flash tutorial
Why are Backchannels Important?
Backchanneling skills are important for people wishing to be able to function as supportive, cooperative listeners. They are also of scientific interest, as they are the most accessible example of the real-time responsiveness that underpins many successful interpersonal interactions.
Where Can I Hear Audio Clips with Backchannels?
English: Excerpts 02, 04, and 05 at Discourse Achievement I, example 6.14 at Sequence Organization in Interaction (both by Schegloff), and examples 1, 2, 5, 9, 10, 13, 23, 25, 26, and 29 at Conversational Grunts.
Arabic: here
How Can I Teach Students to Backchannel Properly?
It can be helpful for learners to listen repeatedly to dialogs and observe the patterns of backchanneling. This requires actual unrehearsed dialogs, not acted conversations, since they typically follow different rules.
It can also be helpful for learners to practice both roles: active listening by producing backchannels appropriately, and engaging talk by providing clear opportunities for the listener to backchannel. (Sample short lesson plan)
Why Did You Make this Page?
While working on ways to make spoken dialog systems more usable (link), I have learned a lot about backchannels. I created this page to make the key facts more accessible to language learners and language teachers.