Human communication requires interlocutors to mutually understand each other. Previous research has suggested inter-brain synchrony as an important feature of social interaction, since it has been observed during joint attention, speech interactions and cooperative tasks. Nonetheless, it is still unknown whether inter-brain synchrony is actually related to successful face-to-face communication. Here, we use dual-EEG to study if inter-brain synchrony is modulated during episodes of successful and unsuccessful communication in clear and noisy communication settings. Dyads performed a tangram-based referential communication task with and without background noise, while both their EEG and audiovisual behavior was recorded. Other-initiated repairs were annotated in the audiovisual data and were used as indexes of unsuccessful and successful communication. More specifically, we compared inter-brain synchrony during episodes of miscommunication (repair initiations) and episodes of mutual understanding (repair solutions and acceptance phases) in the clear and the noise condition. We expect that when communication is successful, inter-brain synchrony will be stronger than when communication is unsuccessful, and we expect that these patterns will be most pronounced in the noise condition. Results are currently being analyzed and will be presented and discussed with respect to the inter-brain neural signatures underlying the process of mutual understanding in face-to-face conversation.