I will talk about the technology behind brainwave entrainment through sound, including binaural beats, monaural beats and isochronic tones.
I will present a description of the different brain wave patterns further down to make understanding of this article easier.
Binaural beats refer to introducing one tone to one year and another tone, with a small variation in pitch (i.e. frequency), to the other year. The difference in frequency between these two tones must correspond to the brain frequency desired. For example, if one tone of 460 hertz is presented to one year and another tone of 450 hertz is presented to the other year, the difference in frequency will be 460 – 450 = 10 hertz, which corresponds to alpha waves being induced in the brain.
Stereo headphones must be used for this technology to work, otherwise it is not possible to introduce a different frequency to each ear in an effective way.
Monaural beats involve mixing two different tones before they are presented to the ears. This creates a beat type pattern, which induces a meditation state in the brain.
Isochronic tones refer to tones presented to the ears in a quick on and off pattern. In other words, a quick cycle of tone and silence is continuously generated.
Both monaural beats and isochronic tones can be listened either on speakers or headphones, but in order for them to be effective, background noise must be kept to a minimum.
In addition, neither monaural beats nor isochronic tones are capable of inducing the deeper delta brain waves. Binaural beats on the other hand are capable of producing deep delta waves in the brain.
A Description of the Different Brain Wave Patterns
Brain waves result from the electrical activity that happens in the brain. This electrical activity happens because the brain cells, which are called neurons, communicate with each other through electrical impulses.
This electrical activity happens in a cyclic, wave like pattern, which varies due to factors like state of mind (relaxed, anxious, etc) and being awakened or sleeping.
Usually people have all types of brainwaves happening at the same time, but one frequency will be more predominant than the others.
Follow below a description of the different types of brainwaves:
Gamma (30-100 cycles per second (Hz)): this frequency happens in certain areas of the brain during processing of mental or motor function. Unlike what happens with the other brain frequencies, gamma waves are never a dominant pattern.
Beta (13 – 30 cycles per second (Hz)): predominant brain wave pattern when a person is awakened. This frequency is associated with alertness and concentration.
Alpha (8 – 13 cycles per second (Hz)): brain wave pattern associated with relaxed concentration state and feelings of contentment and peace.
Theta (4 – 8 cycles per second (Hz)): this brain wave pattern happens during REM (rapid eye movement) sleep. When the person is awakened, the more this frequency is present the greater the creativity and better the memory.
Delta (0 – 4 cycles per second (Hz)): brain frequency of dreamless sleep. Emotional and physical repair take place in this frequency.