Hyperscanning refers to obtaining simultaneous neural recordings from interacting participants.
EEG hyperscanning is becoming increasingly popular since it allows researchers to explore the interactive brain with a high temporal resolution. We described and provided customized implementations of EEG hyperscanning setups using hardware and software from different manufacturers (paper). A proper EEG hyperscanning implementation should allow perfectly synchronized but independent recordings. This implies individual electrical Ground, Reference and power sources (batteries).
In the case of EEG hyperscanning setups dedicated to the study of verbal communication, it is highly desirable to include the audio signal as an extra channel in the recording.