The Science Behind Brainwave Stimulation

Posted: August 1, 2008 in Articles, Timeless

Neurostimulation Research
by Transparent Corp

What are Brainwaves? When a neuron is fired in the brain it emits a charge of electricity for about a millisecond. Since billions of neurons are constantly firing on and off in the brain, this tends to produce a “wave” effect that has been popularly referred to as brainwaves. Sensitive medical equipment (EEG, electroencephalography), is used to detect brainwaves by measuring the electricity levels over areas of the scalp.

With the discovery of brainwaves came the discovery of various bands and subcategories of brainwaves (measured in hertz or “frequencies” ranging from .3 – 40). Depending on what is going on in a person’s head, the brain emits a large variety of brainwaves. For instance, the brainwaves of a sleeping person are vastly different than the brainwaves of someone wide awake.

Over the years, more sensitive equipment has brought us closer to figuring out exactly what various brainwaves represent and with that, what they mean about a person’s health and state of mind.


Entrainment is a principle of physics. It is defined as the tendency for two oscillating bodies to lock into phase so that they vibrate in harmony. It is also defined as a synchronization of two or more rhythmic cycles. The principles of entrainment are universal, appearing in chemistry, neurology, biology, pharmacology, medicine, astronomy and more.

CASE IN POINT: While working on the design of the pendulum clock in 1656, dutch scientist Christian Huygens found that if he placed two unsynchronized clocks side by side on a wall, they would slowly synchronize to each other. In fact, the synchronization was so precise not even mechanical intervention could calibrate them more accurately.

A clock is a simple example of a system responding to entrainment, but the same rules apply to more complex systems such as the brain. For example, when the brain is presented with a stimulus, it emits an electrical charge in response, called a cortical evoked response. If presented with a repeating stimulus, the brain responds by synchronizing these electric cycles to the same rhythm. This is commonly called the Frequency Following Response (or FFR ). The stimulus itself can be nearly anything – a physical vibration, a flash of light or a pulse of sound, which is what our programs focus on providing.

What is Brainwave Entrainment?

Brainwave Entrainment refers to the brain’s electrical response to rhythmic sensory stimulation, such as pulses of sound or light.

When the brain is given a stimulus, through the ears, eyes or other senses, it emits an electrical charge in response, called a Cortical Evoked Response (shown below). These electrical responses travel throughout the brain to become what you “see and hear”. This activity can be measured using sensitive electrodes attached to the scalp.


When the brain is presented with a rhythmic stimulus, such as a drum beat for example, the rhythm is reproduced in the brain in the form of these electrical impulses. If the rhythm becomes fast and consistent enough, it can start to resemble the natural internal rhythms of the brain, called brainwaves. When this happens, the brain responds by synchronizing its own electric cycles to the same rhythm. This is commonly called the Frequency Following Response (or FFR ):

brainwave entrainment

FFR can be useful because brainwaves are very much related to mental state. For example, a 4 Hz brainwave is associated with sleep, so a 4 Hz sound pattern would help reproduce the sleep state in your brain. The same concept can be applied to nearly all mental states, including concentration, creativity and many others. It can even act as a gateway to exotic or extraordinary experiences, such as deep meditation or “lucid dreaming” type states.

If you listen closely to most NP2 Audio/Visual Sessions, you will hear small, rapid pulses of sound. These pulses may be harder to detect if you turn off Tones, but Noise and Background Sounds are also embedded within them. As the session progresses, the frequency rate of these pulses is changed slowly, thereby changing your brainwave patterns and guiding your mind to various useful mental states.

Further Reading

Bermer, F. “Cerebral and cerebellar potentials.” Physiological Review, 38, 357-388.

Chatrian, G., Petersen, M., Lazarte, J. “Responses to Clicks from the Human Brain: Some Depth Electrographic Observation.” Electroencephalography and Clinical Neurophysiology, 12: 479-487

Gontgovsky, S., Montgomery, D. “The Physiological Response to “Beta Sweep” Entrainment.” Proceedings AAPB Thirteenth Anniversary Annual Meeting, 62-65.

Oster, G. “Auditory beats in the brain.” Scientific American, 229, 94-102.

Shealy, N., Cady, R., Cox, R., Liss, S., Clossen, W., Veehoff, D. “A Comparison of Depths of Relaxation Produced by Various Techniques and Neurotransmitters by Brainwave Entrainment” – Shealy and Forest Institute of Professional Psychology A study done for Comprehensive Health Care, Unpublished.

Siever, D. “Isochronic Tones and Brainwave Entrainment.” Unpublished, but available through his book the Rediscovery of Audio-Visual Entrainment.

Walter, V. J. & Walter, W. G. “The central effects of rhythmic sensory stimulation.” Electroencephalography and Clinical Neurophysiology, 1, 57-86.

More on Brainwaves:

Brainwave Bands

There are certain bands (subcategories) of brainwaves that are related to specific functions of the body and mind. In fact, you can tell a lot just by observing a person’s brainwave patterns for a short period of time. For instance, anxious people tend to produce an overabundance of high Beta waves while people with ADD/ADHD tend to produce an overabundance of low Alpha/Theta brainwaves.

Brainwave stimulation can be a very effective treatment for many types of mental and physical disorders. It can also be a gateway into exotic or extraordinary mental states.

Dominant Brainwaves

The brain is constantly emitting nearly every type of brainwave. However, based on the strength of the certain bands of brainwaves, and depending on where the EEG electrodes are placed on the scalp, a person can be said to be “in” a certain brainwave. As you are reading this, you are (assumedly) wide awake and are most likely producing more Beta brainwaves than any other type. So you could be said to be “in” Beta.

Mental States

By stimulating the brain to produce or decrease certain brainwaves bands, we can induce a huge variety types of mental states and emotional reactions, including meditation, excitation, motivation, anxiety, irritation, sexual excitement, relaxation, spiritualism and more.

For instance, if we were to embed Alpha waves into music, listening to it would be very relaxing, even causing your body to physically relax. If we embedded Theta waves into music, people might even fall asleep!

Specific Brainwave Frequencies

In addition to bands of brainwaves, very specific frequencies have been shown to have certain effects, such as stimulating the release Serotonin or human growth hormone (HGH).

Brainwaves Types



Mental State / Sub-Categories (bands)

Beta 12hz – 38hz Wide awake. This is the state you are normally in from the moment you wake up to the time you go to sleep at night. Usually, this state in itself is uneventful, but don’t underestimate its importance. Entraining SMR and Beta 1 in particular can be extremely beneficial to people with mental or emotional disorders such as insomnia, depression or ADD. This band can also be used for increasing focus or even IQ!

  • SMR (sensorimotor rhythm) (12 – 15Hz): Related to body motion. Increasing this can result in relaxed focus, improved attentive abilities. Generally a good thing to increase.
  • Beta 1 (15 – 20 Hz) – Can increase mental abilities, IQ, focus
  • Beta 2 (20 – 38Hz) – Highly alert, but also anxious
Alpha 8hz – 12hz Awake but relaxed and not processing much information. When you get up in the morning and just before sleep, you are naturally in this state. When you close your eyes your brain automatically starts producing more Alpha waves.

Alpha is usually the goal of experienced mediators, but to enter it using this program is incredibly easy. You can also use this state for effective self-hypnosis and mental re-programming.

Theta 3hz – 8hz REM sleep or extreme relaxation. Lucid dreaming and OBEs can also occur at this state. Other “weird” and often “paranormal” experiences have been reported while in or very near the Theta state.

Theta can also be used for hypnosis, accelerated learning and mental programming (using pre-recorded suggestions).

  • Theta 1 – (3 – 5 Hz) The suppression of this band can improve concentration, attention and reduce hyperactivity.
  • Theta 2 – (5 – 8 Hz) Very relaxed and dreamful sleep. Life-Transforming, paranormal, and spiritual experiences are most common at this band.
Delta 0.2hz – 3hz Deep, dreamless sleep. Delta is the slowest band of brainwaves. When your dominant brainwave is Delta, your body is healing itself and “resetting” its internal clocks. You do not dream in this state and are completely unconscious. Entrainment of the brain at this level is all but impossible. Most of the time, people wishing to enter Delta will have to settle for deep Theta and hope than their mind “drifts” down into Delta on its own.

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