What are binaural beats and how do they work?
What are Binaural Beats (Basic Definition)
‘Binaural Beats’ is a term given to a measured change in brain activity when presented with audio stimulus. When a person is presented with a stereo sound with two different tones – the brain produces a response (binaural beat) which is hearing and responding to the difference between the tones, not the actual tones themselves.
At Mindfit we do not use different tones when creating Binaural Beats (tones can be very annoying and distracting) – We create a slight different in the notes or sounds presented in the left and right channel of the music.
The sample will first play in it’s original form and then again with the tonal changes required to produce the Binaural Beat effect. This sample has a high volume of difference between the tones compared to the actual Hypnosis sessions, so that you can really hear the ‘wavy effect’ of the difference in how each side sounds.
Sample of music encoded with Binaural Beats Notice how the Music becomes ‘wavy’ with the embedded beats
Detailed Definition of Binaural Beats
Binaural beats are auditory brain-stem responses which originate in the superior olivary nucleus of each brain hemisphere. They result from two different auditory impulses or sounds, heard from opposite ears. This binaural beat is consciously heard as the human hearing range is from 20-20,000 Hz. Rather it is perceived as an auditory beat and theoretically is being used coach certain brain rhythms from what is called the frequency-following response (the tendency for the brain to resonate at the frequency of an external stimulus).
How It Works On The Brain
When signals of two different frequencies (sounds) are presented, one to each ear, the brain detects phase differences between these signals. The brain processes this anomalous information differently when these phase differences are heard with stereo headphones or speakers. A perceptual integration of the two signals in perceived in the brain, producing the sensation of a third “beat”. The difference between the signals waxes and wanes (this is the “wavy” sound heard in the hypnotic sessions) as the two stereo sounds mesh in and out of phase. The binaural beat is perceived as a fluctuating rhythm at the frequency of the difference between the two auditory inputs.
How Binaural Beats creates a Hypnotic Response
Binaural beats can easily be heard at the low frequencies (< 30 Hz) that are characteristic of the EEG spectrum (Oster, 1973). This perceptual phenomenon of binaural beating and the objective measurement of the frequency-following response (Hink, Kodera, Yamada, Kaga, & Suzuki, 1980) suggest conditions which generate brain waves activity and altered states of consciousness (hypnotic trance).
|> 40 Hz||Gamma waves||Higher mental activity, including perception, problem solving, fear, and consciousness|
|13–39 Hz||Beta waves||Active, busy or anxious thinking and active concentration, arousal, cognition, and or paranoia|
|7–13 Hz||Alpha waves||Relaxation (while awake), pre-sleep and pre-wake drowsiness, REM sleep, Dreams|
|8–12 Hz||Mu waves||Sensorimotor rhythm Mu_rhythm, Sensorimotor_rhythm|
|4–7 Hz||Theta waves||deep meditation/relaxation, NREM sleep|
|< 4 Hz||Delta waves||Deep dreamless sleep, loss of body awareness|
There are a growing amount of research efforts reporting changes in consciousness associated with binaural-beats. “The subjective effect of listening to binaural beats may be relaxing or stimulating, depending on the frequency of the binaural-beat stimulation” (Owens & Atwater, 1995). Binaural beats in the delta (1 to 4 Hz) and theta (4 to 8 Hz) ranges have been associated with reports of relaxed, meditative, and creative states (Hiew, 1995), and used as an aid to falling asleep. Binaural beats in the alpha frequencies (8 to 12 Hz) have increased alpha brain waves (Foster, 1990) and binaural beats in the beta frequencies (typically 16 to 24 Hz) have been associated with reports of increased concentration or alertness (Monroe, 1985) and improved memory (Kennerly, 1994).
Mind-Fit uses the differing rates of Binaural beat stimulation during the induction and therapy parts of its sessions to aid in the progressive relaxation acquired when entering the Hypnotic state.