Binaural Beat Frequencies

Robert Monroe made a remarkable discovery when he learned that the brain processes sound using the super positional effects of interference.

What Are Binaural Beats?

Binaural Beats are the sensation of hearing a throbbing sound, when in fact, you are hearing two constant amplitude sounds in separate ears.

Why Is This Remarkable?

This is remarkable for two reasons.

• It provides a way to deliver very low frequencies to the brain.
  
  
• It indicates that our hearing is more sensitive and responsive to phase than previously thought.

Our hearing ranges from about 16 Hz to 20,000 Hz. At times in our research, we would like to expose our sound therapy clients to frequencies below 16 hertz, but, we are unable to do that since they are inaudible. Binaural Beats to the rescue. By generating two higher frequencies with the desired difference frequency, we are able to generate the low frequency sounds.

For example, let's say we wanted to support our client with a 4 Hz tone. It is impossible to hear such a low frequency and very difficult to generate. However, if we instead play a tone of say, 160 Hz in one ear and 164 Hz in the other, then the brain combines the two separate tones to produce what seems to be a single tone whose amplitude modulates at 4 Hz. This third sound is created in the brain and is called the binaural beat.

Hearing Phase

It is just becoming apparent now, and with the invention of Hugo Zuccarell's Holophone Sounds, that the ears are extremely sensitive to phase. Our current understanding of the brain and how it works does not seem to be able to explain how the brain is able to combine the sounds phase information to create the binaural beat effect.

It is interesting to realize that this effect is largely a "sonic illusion," similar to an optical illusion. Our brain processes the sounds and indicates that it is hearing a single sound which is strong varying in amplitude, where, in fact, we are hearing a constant volume sound in each ear. We theorize that this phase processing is strongly related to our ability to detect the location of a sound.

Hopefully we will be able to expand our knowledge in this field in the near future.