Backchannel
Backchannel is the ability for the agent to make small noises like “uh-huh”, “I see”, etc. during user speech, to improve engagement of the call. You can set whether to enable it, how often it triggers, what words are used. You will look at the following fields in Create Agent API:
  • enable_backchannel: set to true to enable backchannel. Default to false.
  • backchannel_frequency: When our engine determines that a backchannel is possible and appropriate here, you don’t necessarily always want to backchannel. Humans often only backchannel at some places, not all possible cases. Therefore, this field controls how often the backchannel is triggered, with 0 being never, 1 being always when possible. The default is 0.8.
  • backchannel_words: The words that the agent can use as backchannel. The default is different for each language, and for each voice provider, as some voice provider does not have support for some of the words. The following tab contains the default backchannel words for each language and voice provider. You can overwrite this field to customize the backchannel words. Note that certain voices do not work too well with certain words, so it’s recommended to expeirment before adding any words.
    • 11labs voices: [“okay”, “uh-huh”, “mhmm”, “yah”]
    • openai voices: [“okay”, “uh-huh”, “yah”]
    • deepgram voices: [“okay”, “uh-huh”, “yah”]