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.