[photonic29]

If it dragged dominant EEG frequencies, that would suggest that the effect either alters thalamic pacemaking or otherwise takes over. This audio beat frequency may exist as an analog somewhere locally as changes in average postsynaptic potentials in the auditory cortex, but it would be surprising if the effect grew to a larger sphere of influence. Healthy brains are pretty good at attenuating that kind of insidious network effect.