Full duplex speech models take turns later than humans in conversation
Coupled but Late: Turn-Taking Between Full-Duplex Speech Models in Unscripted Dialogue
Artificial Intelligence
Summary
When two AI speech models talk to each other, the timing of their turn-taking is linked but different from how humans do it. The researchers found that these models wait longer to switch turns, usually around 400-560 milliseconds, compared to humans who switch in about 137 milliseconds. The models seem to react after the other finishes speaking rather than predicting when the turn will end, unlike humans. This study shows that AI conversations have a different rhythm and timing than natural human conversations.
What this means in practice
- •For conversational ai developers: Adjust turn-taking mechanisms in speech AI to reduce unnatural delays in multi-agent conversations.
- •For speech interface designers: Improve user experience by aligning AI response timing closer to natural human conversational rhythms.
Authors
Lichen Zhu, Yueqian Lin, Yiheng Wang, Hai "Helen" Li, Yiran Chen
Abstract
Full-duplex speech models are trained to converse with a person, but they are increasingly made to converse with each other, in self-play data generation, agent societies, and model-based evaluation. In that loop no human absorbs a timing error: each model's turn-taking is the other's input. We ask what timing the loop settles into. Two PersonaPlex-7B instances exchange audio tokens on a shared clock in unscripted conversation, and one floor-transfer rule is applied to them and to Switchboard. Their timing is coupled: re-pairing speakers across conversations destroys it. But the floor changes hands late, at a median of 400-560 ms against 137 ms for humans, and the last 120 ms of the partner's turn, where human projection places a tenth of its transfers, holds 1% of theirs. Delaying one direction of the channel shifts the response one-for-one and leaves the run-up to it empty, consistent with a reactive wait after the perceived end rather than the turn-end projection human timing requires.