I believe these "morphic fields" are theoretically related to the energy that we raise by chanting or other meditations, although I haven't looked super far into it. However, while sound can have power, I believe we must realistically doubt the power of these videos, as the extent of the benefit from these videos is probably little, if anything. Further, it could be harmful if there is the assumption of some major benefit, which might distract someone from their meditations, and so on.
I don't think the people making these videos have any sort of advanced occult knowledge, otherwise they wouldn't be freely spreading it in a Youtube video. It is more likely they just made something up that they thought would work. Of course they sell premium versions on Patreon, and so on, therefore they are financially incentized to promise grand results which are difficult to measure.