Top Resonant entrainment of oscillating systems Resonant entrainment of oscillating systems is a well-understood principle within the physical sciences. The first tuning fork is said to have entrained the second or caused it to resonate. The physics of entrainment apply to biosystems as well. Of interest here are the electromagnetic brain waves. The electrochemical activity of the brain results in the production of electromagnetic wave forms which can be objectively measured with sensitive equipment.
Brain waves change frequencies based on neural activity within the brain.
Top The Discovery Of Binaural Beats Binaural beats were discovered in 1839 by a German experimenter, H. W. Dove. Many evolved species can detect binaural beats because of their brain structure. The frequencies at which binaural beats can be detected change depending upon the size of the species' cranium. Hz the wave length of the signal is longer than the diameter of the human skull. Thus, signals below 1000 Hz curve around the skull by diffraction.