In sound healing training, brainwave entrainment is a method to stimulate brain's electrical response to rhythmic sensory stimulation, such as pulsating light, sound, or electromagnetic field.
The external (entraining) pulses evoke the brain’s frequency following response to align to the frequency of a given signal. This method is commonly used to induce many brainwave states, such as relaxation, trance, enhanced focus, meditative state, or sleep induction.
What is being presented in sound therapy courses today as brainwave entrainment either with sound or light is not a new invention. Ceremonial chambers, acoustically tuned to specific brainwave patterns, have been dating back to the Bronze Age. Ancient Greeks projected sunlight through spinning wheels to induce altered states by looking at the flickering shining.
The pioneer of "out of body experiences" (astral projection), Robert Monroe, designed a series of verbal tutorials superimposed with binaural beats. His audio programs help the listener to achieve the state in which controlled separation from the physical body becomes possible.
More tips about the implementation of brainwave entrainment as well as, practical exercises are given in Sound Healing Training Certification Program.
Brainwave entrainment is a great way to enter the states that are otherwise difficult to reach with no external help. Any frequency with stable periodicity evokes a cortical response.
Through the exposure of sensory organs to periodically pulsating signals, the brain eventually synchronizes its dominant brainwave frequency with that of the external stimulus. That's how the phenomenon of brainwave entrainment takes place. Entrainment shifts our mental state by boosting one frequency to be louder than others. However, it's important to mention that this method has only a temporary effect. When the source of the external impulse is removed (or turned off), the brain activity goes back to its habitual function.
The habitual brainwave patterns and habitual brain activity though can be adjusted by prolonged training (like training muscles in the gym).
The development of digitally encoded audio beats, strobe lights, or low-energy electromagnetic fields has not stopped since the 1970s. There is a lot of marketing hype around brainwave entrainment. Today you can find a wide variety of different gadgets on the market, including apps and music files that claim to help stabilize brainwaves. In an advertisement for these products, you may see promises of increasing IQ, promoting weight loss, getting rid of addictions, enhancing creativity, improving concentration, inducing spiritual states, and more.
While these claims are not entirely valid, they are not altogether false either. In practice, the claims are based on an overly simplistic view of brainwave functions.
The deficiency of a certain brainwave pattern in all areas of the brain is a pretty rare diagnosis. Usually, the distribution of brainwaves is uneven, with excess in one area and a deficiency in another. Also, speaking of brainwave distribution, it is important to keep in mind that one person is different from another.
Boosting a particular brainwave state may be beneficial for one person and disturbing for another. Without knowing the starting position of each individual, entrainment can be rather ‘hit and miss’. If brainwave entrainment leaves you with any discomfort, you’re probably enhancing a range of brainwaves that are already excessive in some areas of your brain. The best thing, in this case, would be to get a brain map to see what your brain’s strengths and weaknesses are.