In my last post, “The Science Behind Sound Healing,” I explained how brainwaves readily synchronized with externally produced sound waves through a process called entrainment. Using this principle, we can induce brainwaves that correlate to desirable states of consciousness such as Alpha, Theta and Delta wavelengths, which have been regularly observed in practitioners of deep meditation such as Yoga Nidra and Vedanta .
Alpha, Theta, and Delta wavelengths (0.5 Hz - 12 Hz), are inaudible to the human ear, but can be perceived in the brain using a process called binaural hearing. When the brain is simultaneously exposed to two slightly different frequencies within a close range (for example 154 Hz and 150 Hz), a third frequency is perceived internally, expressing the difference between the two .
Binaural Hearing Example:
Externally Produced Audible Sound Frequencies
– 150 Hz
Internally Perceived Brain Frequency (Theta)
Ancient and traditional sound technologies such as gongs, chimes, and singing bowls were made to vibrate within a small range of frequencies, as if our ancestors were privy to the newly emerging sciences of binaural hearing and entrainment. For example, studies on the frequencies emitted by Tibetan Buddhist chimes called Ting-Sha’s show expression of wavelengths between 4 and 8 Hz, “the range of brain waves that occurs during meditation” notes Mitchell L. Gaynor M.D., Oncologist and Clinical Assistant Professor of Medicine at Weill Medical College of Cornell University .