S2 File

MEG raw data obtained from two subjects speaking in turns with a sampling rate of 600 Hz. Anony_SiteA_(number).fif files contains the MEG of site A (the Hokkaido University Medical and Dental Research Building; customized, Elekta Neuromag; 101 ch.) and the voice signal of the subject at site A (EEG 03) and that of the subject at site B (EEG 04). The voice signals were used to identify voice onset of the subject at the opposite site. Anony_SiteB_(number).fif files contains the MEG of site B (Hokkaido University Hospital; VectorView, Elekta Neuromag, 306 ch.). The TTL signals (STI 014 of both files) can be used for time adjustment between the MEG of site A and site B. Other TTL signals are irrelevant for this analysis. Anony_Site(A/B)_e.fif files are the environmental magnetic fields without subjects to monitor noise levels. Note: The MEG device of site A was a customized one. Sensors with following number were used only for reference; [5,8,13,20,24,26,31,37,46,51,55,60,63,70,77,80,84,90,93,96,97,98,99,100,101]. The names of the subjects have been removed to anonymize the data.