Hmm, those experts seem right.

Also, your brain's natural beat can interfere with the recording. If your brain emanates non-delta brain waves, that will sure turn the recording wrong. Believe me as I studied brain's effect on binary executables for three years now.
So, how can the brain's delta-beat be achieved? When recording started,
immediately enter meditation, deep trance, anabiosis or coma state. Every missed second matters - use light drugs if necessary.
gl && hf