Interaction between auditory and visual stimulus relating to the vowel sounds in the auditory cortex in humans: a magnetoencephalographic study

We investigated the difference of M100's peak latency, maximum amplitude, dipole location and moment, following vowel sound /a/, with two conditions: (a) showing static face with closed mouth, (b) showing the same face with mouth movement using an apparent motion, appearing to pronounce /a/. In results, there were no significant differences in the M100 between the two conditions. These results indicated that vowel sound perception in the auditory cortex was not affected by mouth movement, at least in the primary acoustic information process.