Evaluation of methods and techniques for conversational and multimodal spoken dialogue systems is complex, as is gathering data for the modeling and tuning of such techniques. This article describes MushyPeek, an experiment framework that allows us to manipulate the audiovisual behavior of interlocutors in a setting similar to face-to-face human-human dialogue. The setup connects two subjects to each other over a Voice over Internet Protocol (VoIP) telephone connection and simultaneously provides each of them with an avatar representing the other. We present a first experiment which inaugurates, exemplifies, and validates the framework. The experiment corroborates earlier findings on the use of gaze and head pose gestures in turn-taking. (Contains 5 figures and 1 footnote.)