  During a conversation, individuals take turns speaking and engage in
exchanges, which can occur smoothly or involve interruptions. Listeners have
various ways of participating, such as displaying backchannels, signalling the
aim to take a turn, waiting for the speaker to yield the floor, or even
interrupting and taking over the conversation.
  These exchanges are commonplace in natural interactions. To create realistic
and engaging interactions between human participants and embodied
conversational agents (ECAs), it is crucial to equip virtual agents with the
ability to manage these exchanges. This includes being able to initiate or
respond to signals from the human user. In order to achieve this, we annotate,
analyze and characterize these exchanges in human-human conversations. In this
paper, we present an analysis of multimodal features, with a focus on prosodic
features such as pitch (F0) and loudness, as well as facial expressions, to
describe different types of exchanges.
