Theta oscillations track and reinstate the dominant activity carried in the auditory envelope. A, Source localization of theta phase similarity between the brain oscillations and auditory speech envelope during synchronous or asynchronous movie encoding (significant t values). The tracking of the dominant theta oscillations carried by the auditory speech envelope was reflected across extended bilateral neocortical networks and similarly during synchronous and asynchronous movie, which suggests that audiovisual asynchrony did not impact auditory tracking per se. B, Theta phase similarity between the theta oscillations from the left and right auditory cortices (X-axis) and the theta oscillations conveyed by auditory speech envelope (Y-axis) during successful retrieval (t values). The X-axis represents time for the MEG theta phase, and the Y-axis represents time for the speech envelope. C, Theta phase similarity difference between the synchronous and asynchronous conditions in the left and right auditory cortices during successful retrieval. The accuracy of the reinstatement was modulated by the audiovisual asynchrony in the left but not the right auditory cortex. The time-points from the significant cluster are depicted in full color and outlined, while nonsignificant data are masked with transparency. D, Virtual sources localized in the left and right auditory cortices used for the phase similarity analysis (respectively the left and right Heschl’s gyrus; LHG and RHG).