Silence and overlap in chat and chunk phases of multiparty casual conversation

Casual conversation, 'talk for the sake of talking', is often multiparty, with no clear practical goal, and can last up to several hours.Longer conversations proceed in phases of chat and chunk, where chat is highly interactive and chunks are dominated by one speaker.It is likely that prosodic features will vary between the two phases.Greater understanding of such casual conversation is vital to the design of humanlike artificial dialogue, and the need for clearer modelling has prompted our explorations into silence and overlap in six manually segmented long (c. 1 hr) informal multiparty conversations.We test automatic segmentation on the data, and find manual segmentation is necessary to accurately capture speech activity.We analyse speech activity at the end of intervals where one participant speaks in the clear for a second or more, and categorise patterns of overlap and turn change or retention in chat and chunk phases.We also report on a study of a subset of our dataset, taken from a 5-party conversation, comprising over 200 manually annotated intonational phrases (IP) adjacent to silences and overlaps, analysing IPfinal tunes with the IViE intonational transcription system, and measuring IP duration to investigate prosodic patterns in the different conditions.