From "um" to "yeah": Producing, predicting, and regulating information
  flow in human conversation
Claire Augusta Bergey Simon DeDeo
Conversation demands attention. Speakers must call words to mind, listeners
must make sense of them, and both together must negotiate this flow of
information, all in fractions of a second. We used large language models to
study how this works in a large-scale dataset of English-language conversation,
the CANDOR corpus. We provide a new estimate of the information density of
unstructured conversation, of approximately 13 bits/second, and find
significant effects associated with the cognitive load of both retrieving, and
presenting, that information. We also reveal a role for backchannels -- the
brief yeahs, uh-huhs, and mhmms that listeners provide -- in regulating the
production of novelty: the lead-up to a backchannel is associated with
declining information rate, while speech downstream rebounds to previous rates.
Our results provide new insights into long-standing theories of how we respond
to fluctuating demands on cognitive resources, and how we negotiate those
demands in partnership with others.