Communicative listener feedback is a prevalent coordination mechanism in dialogue. Listeners use feedback to provide evidence of understanding to speakers, who, in turn, use it to reason about the listeners' mental state of listening, determine the groundedness of communicated information, and adapt their subsequent utterances to the listeners' needs. We describe a speaker-centric Bayesian model of listeners and their feedback behaviour, which can interpret the listener's feedback signal in its dialogue context and reason about the listener's mental state as well as the grounding status of objects in information state.