Cortisol is an arousal hormone, stimulating alertness and attention. Cortisol levels rise and fall in connection to circadian rhythms—cortisol levels rise to their peak levels first thing in the morning, just in time for you to be active for the day. Too-high cortisol levels are associated with insomnia, as well as more time spent in light sleep, rather than deep sleep.
Beta: These brainwaves are associated with high levels of alertness and arousal. When beta brainwave patterns dominate, we’re primed to focus and concentrate, to make decisions and think analytically. When you’re analyzing an issue at work, you’re probably in a beta-dominant state. Beta waves are fast, with a higher frequency (between 15-40 hertz). At the higher levels of this range, beta waves are associated with anxiety.
In shamanic traditions, drums have long been used to transport the shaman out of his or her body into other realms of reality through the use of constant rhythmic vibrations. Researcher Melinda Maxfield, studying the Shamanic State of Consciousness, found that the steady rhythmic beat of the drum struck 4.5 times per second was the key to transporting a shaman into the deepest part of his shamanic state of consciousness. With the invention of the EEG (electroencephalograph) Biofeedback researchers discovered that theta brain waves oscillate at 4.5 beats, or cycles, per second. In direct correlation, we see similar effects brought on by the constant and rhythmic drone of Tibetan Buddhist chants that transport the monks and even other listeners into realms of blissful meditation.
How does brainwave entrainment work? Consistent, precisely engineered audio frequencies in the form of binaural beats cause the brain’s frequencies to match the stimulus. Your brain perceives two beats with slightly different frequencies (which are inaudible to the ear) through your headphones. It takes the difference between the two, and matches its own frequency to it. This is called the “frequency following” response.
Cory Allen [b. 1982] is a composer and mastering engineer living in Austin, Texas. His work focuses on the cultivation of human perception with the intent of altering the listener's state of consciousness. Allen's music is deep, patient, meditative, highly-conceptual and often composed by implementing self-organizing structures, rule-based performances, set pitch classes and a wide variety of instruments.
Binaural beats were the first method discovered for brainwave entrainment and works by delivering tones of different audible frequencies to the two ears with the difference in frequency between the two tones being the frequency of entrainment. The difference in frequency between the two tones must be less than 30 hertz, and this resulting frequency is called a beat or the target frequency, and it is processed in a brain region called the olivary body. When listening to such tones with stereo headphones, the two hemispheres of the brain become synchronized at the target frequency.
Over-arousal in certain brain areas is linked with anxiety disorders, sleep problems, nightmares, hyper-vigilance, impulsive behaviour, anger/aggression, agitated depression, chronic nerve pain and spasticity. Under-arousal in certain brain areas leads to some types of depression, attention deficit, chronic pain and insomnia. A combination of under-arousal and over-arousal is seen in cases of anxiety, depression and ADHD. more...
Years of scientific study combined with the personal testimony of thousands of people establish that using brainwave entrainment techniques positively affects the physical, mental, emotional, and spiritual well-being in a majority of users. You can easily take advantage of these powerful methods of personal self-help and self-improvement by downloading a variety of entrainment music right now.

Why is exposure to these soundwaves helpful to sleep and relaxation? Science shows that exposure to binaural beats can create changes in the brain’s degree of arousal. Listening to these sounds that create a low-frequency tone, research indicates, triggers a slow-down to brainwave activity—and that may help you relax, lower your anxiety, and can make it easier for you to fall asleep and sleep more soundly.
Critics, like Owen Flanagan, PhD, believe that Hanson, and those like him, are overextending the results of current scientific studies.[citation needed] In his book Bodhisattva’s Brain: Buddhism Naturalized, Flanagan presents a more conservative viewpoint of current scientific research and cautions readers against the seemingly exciting results of recent studies.[20] Flanagan does not believe current science supports the idea that positive emotion can be strengthened in the same way that stroke victims can recover use of limbs with use.[20] Flanagan does acknowledge that meditation may be beneficial in some way, but the mechanism of how meditation affects the brain is still clouded.[20] Similarly, Awasthi argues that Meditation is non-specific to the research studies showing clinical efficacy in some cases, though mechanisms remain unclear.[21] Flanagan and Hanson use many of the same scientific studies to attempt to support their differing viewpoint, but both authors identify the need and importance of future studies investigating meditation.

Your brain cells reset their sodium & potassium ratios when the brain is in Theta state. The sodium & potassium levels are involved in osmosis which is the chemical process that transports chemicals into and out of your brain cells. After an extended period in the Beta state the ratio between potassium and sodium is out of balance. This the main cause of what is known as "mental fatigue". A brief period in Theta (about 5 - 15min) can restore the ratio to normal resulting in mental refreshment.  

By the 1980s, entrainment technology had merged with advancements in microelectronics technology, making it possible to develop even more sophisticated audio and visual brainwave entrainment products for the marketplace. In the last two decades, a number of scientific studies have reported brainwave entrainment as an effective remedy for ADD, academic learning problems, and improving memory and cognition.

Brainwave Entrainment is an assisted form of meditation using pulses of sound. Entrainment is a process of synchronizing two different beats to become harmonious. Brainwave entrainment works by pulsing a different sound in each ear to stimulate the brain into altered states of consciousness. Examples including Binaural Beats and Isochronic Tones, which are best experienced with headphones to assist with relaxation, deep sleep and focus.

The results of using EquiSync for only 3 months have been phenomenal! Profound and positive changes have occurred , and continue to occur, in my being. These transformations have become obvious to family and friends as well. I am 71 yrs old and feel better than when I was in my thirties. My energy levels remain high with less sleep. I work out at the gym vigorously five days a week – bicycling and swimming are part of the regimen as well. I volunteer services at Hospice and nursing homes. My short term memory has improved to the point that others remark on my remembering their names after meeting them only once several weeks in the past. Sometimes I find that I’m reading fine print without my glasses. I spent the greater portion of my “productive” years as a monk but had lost the ability to meditate due to the development of A.D.D. Now my ability to stay focused and concentrate has remarkably returned and am reaching meditative states that I’ve not reached in years. Each new day is now seen as another opportunity to serve.
Basically, "two ears." One usage of the word is "binaural recording," which is a form of stereo recording meant to take advantage of the spatial perception of the human ear. Recordings are usually done using a pair of microphones mounted to a dummy head with roughly accurate models of the human outer ear, and the result when played back through headphones is extremely realistic and comparable to surround sound, though following an entirely different recording model. Binaural recordings aren't woo at all, and have nothing to do with binaural beats.[citation needed]
First of all, thank you for a most remarkable achievement. I have tried products in the past that purported to synchronize meditation-level brain waves — usually overlain by sappy new-age music composed by non-composers — and was invariably disappointed. However, I have been using your Equisync II and Equisync III recordings for a few weeks now and the results are truly astonishing and live up to the claims on your website.
A crossover RCT of a single session of theta stimulation in four healthy adults reported no significant improvement in verbal fluency or attention associated with the intervention and a reduction in immediate recall. Controlled comparisons reported significant benefit from the intervention in all three outcomes measured. Six pre/post studies reported significant benefit from the intervention for 19 of 28 cognitive outcomes.
Binaural beats are created when two tones are played simultaneously, one in each ear. As long as the difference between the two frequencies is less than 30 hertz, the brain perceives the difference in the tones as a “beat” which, if listened to with enough focus, the brain will begin to follow (this is known as the “frequency following response”). By changing the difference between the two beats, the brain will change its wavelength and enter into different “states” of being.
Brainwave entrainment through the use of binaural beats is a scientific method that helps you go from alert to relaxed to asleep within minutes by using a process to alter your brainwaves. Sounds like something straight out of a science fiction novel, but brainwave entrainment is a very real and very effective way to help you sleep. Your alertness is linked to the dominant frequency of your brainwaves. So if you’re feeling alert and focused, your brainwaves are in the beta frequency but if you’re feeling relaxed, they’re likely to be in the alpha state. To sleep, your brainwave frequency needs drop to a slow delta. This can be hard, especially after a busy day. Your brain stays alert, preventing you from relaxing. By using Binaural Beats, you can quickly induce the frequencies associated with sleep in your brain within minutes.  Scientists discovered that the brain synchronises itself to a dominant frequency. So by inducing a new lower frequency with binaural beats, your brain begins to lower its own frequency to match this new frequency. It’s a powerful technology that I’ve been using myself for years with very good results.
According to the Wikipedia entry “(i)n acoustics a beat is an interference pattern between two sounds of slightly different frequencies, perceived as a periodic variation in volume whose rate is the difference of the two frequencies.” Further, a binaural beat is “… an auditory illusion perceived when two different pure-tone sine waves, both with frequencies lower than 1500 Hz, with less than a 40 Hz difference between them, are presented to a listener dichotically (one through each ear)”. If the two frequencies are, say, 5 Hz apart as in 500 and 505 Hz, then a third tone at 5 Hz will be heard in addition to the two pure tones. What this technique allows for is the creation of an apparent auditory signal that can be perceived and that is at a predictable frequency. In this way, relatively low frequencies can be generated that can be easily perceived and that can correspond to the common brainwave frequency bands. These are often categorized as delta (0.5 – 4 Hz), theta (4 – 7 Hz), alpha (8 – 12 Hz), and beta (13 – 16 Hz). You may find somewhat different ranges and bands other than these listed depending on the source you consult. It is also possible to produce flashes of light that can be administered within these frequency bands but there is some risk of inducing seizures in susceptible individuals. While the most common frequency range for inducing seizures is 15 – 25 Hz, unfortunately, the possible range is 1 – 65 Hz, which covers essentially the whole range of standard EEG frequency bands. This makes use of sound stimulation safer than visual or combined audio/visual stimulation. 
You may recognize the "binaural recording" from ASMR, where the technique is often used. This explains why, if you search for "binaural" on YouTube, you get a mixture of two entirely different kinds of results: binaural beats and binaural ASMR recordings. It gets especially confusing in that there's some questionable and/or unexplored science surrounding each one.

Rudy's primary work is on Alzheimer's. In this disease, beta amyloid proteins form plaques in the brain and kill nerve cells eventually leading to dementia. Research from Washington University School of Medicine in St. Louis shows that when people's brains are in a Delta brain wave state, beta amyloid production in the brain ceases and the toxic material is cleared away. One thought is to explore the possibility of using brain entrainment technology to help treat Alzheimer's, but at this point all it is being used for is to help people meditate, relax and dream instantly and effortlessly.

Slip on your headphones, close your eyes and turn out the lights. Within minutes you’ll feel like your brain is being massaged. Soothing Delta frequencies, associated with deep restorative sleep, and subliminal messaging for deep sleep are masterfully woven into gentle music. As your brain cells resonate and your brainwaves entrain with Delta waves, you start to slowly swirl and drift. Delta binaural beats help wash away pestering concerns, allowing you to fall into deep sleep states that bring the refreshing slumber your body and mind need for health, happiness and optimum performance.
It may be that you had the volume too loud, but I would expect you to hear the effects of that straight after you’ve stopped listening, not on a day you haven’t used them. It might be something similar to muscle memory, where you suddenly remembered the sound and sensations it gives you as if you were hearing it again. I don’t know how long you’ve been using this type of thing for, but maybe it’s something that will settle down and disappear once you become more accustomed to the sound.
Earlier evidence out of UCLA suggested that meditating for years thickens the brain (in a good way) and strengthens the connections between brain cells. Now a further report by UCLA researchers suggests yet another benefit. Long-term meditators have larger amounts of gyrification ("folding" of the cortex, which may allow the brain to process information faster) than people who do not meditate. A direct correlation was found between the amount of gyrification and the number of meditation years, possibly providing further proof of the brain's neuroplasticity, or ability to adapt to environmental changes.
Brainwaves are the collective electrical signal of millions of neurons working together in a living brain, producing our sense of alertness – or lack thereof - and producing our experience of reality. As brainwaves change, so does our perception of the world and our inner perception of ourselves. By learning to control our brainwaves, we can achieve specific, desirable mental states, such as feeling more relaxed, less anxious, more creative, more focused, or sleepier.

People with a past history of epilepsy or seizures should NOT use brainwave entrainment. Those with heart disorders or taking mood-altering pharmaceutical drugs should consult a doctor before trying. Also, some of the frequencies within the videos may make you feel sleepy. As a good practice, please do not listen whilst you are operating machinery or vehicles or carrying out any responsible duties.
Brainwave Power Music dedicates ourselves to creating original sound therapy music, using unique Musical Compositions, Binaural Beats and Isochronic Tones as our primary sound elements mixed with different instruments and soundscapes to create a relaxed audio environment. We have one main goal: To help others through our music, be it for physical, emotional, mental or spiritual purposes. We constantly upload new music, and continue to work hard to provide new quality music for everyone.

Meanwhile, the therapeutic benefits of listening to sound and music is a well-established principle upon which the practice of receptive music therapy is founded. The term 'receptive music therapy' denotes a process by which patients or participants listen to music with specific intent to therapeutically benefit; and is a term used by therapists to distinguish it from 'active music therapy' by which patients or participants engage in producing vocal or instrumental music.[37] Receptive music therapy is an effective adjunctive intervention suitable for treating a range of physical and mental conditions.[38]
Well, I finally listened to “Equisync III” after listening to “Equisync I” & the “Equisync II” several times. Let me just say that this put me in another state of consciousness within 7 minutes(guessing) it was beautiful! I meditated throughout the entire 70 minute CD set! It didn’t feel like 70 minutes. I could feel energy in my neck, my solar plexus area and at the brow of my head! Definitely NOT for beginners!
During meditation, people often feel a sense of no space. Scientists investigating the effect of the meditative stateon Buddhist monk's brains have found that portions ofthe organ previously active become quiet, whilst pacified areas become stimulated. Using a brain imaging technique, Dr. Newberg and his team studied a group of Tibetan Buddhist monks as they meditated for approximately one hour. When they reached a transcendental high, they were asked to pull a kite string to their right, releasing an injection of a radioactive tracer. By injecting a tiny amount of radioactive marker into the bloodstream of a deep meditator, the scientists soon saw how the dye moved to active parts of the brain.
There’s also some new stuff I’ve certainly never included in tracks before including some gentle pink noise and brown noise blended together in the background with what’s called phase modulation. This is almost outside of awareness as you’re listening to it. This is how your ear tells what direction a sound is coming from. Does it arrive at your left ear slightly before your right ear? You can modulate that. So, again, it has a very gentle, imperceptible rhythmic quality to it.
Most wisdom traditions have employed methods that allow the subjects' brain waves to slow down such as meditation, [Hindu] kirtan, [Gregorian, Menzuma or Sufi] chanting, Hebrew davening, Native American drum circles and rain chants, Tibetan prayer bowls, and whirling dervishes and African trance dancing. The rhythm of these wisdom tradition technologies actually slows people's brain waves from their normal busy brain frequency we call Beta (13-30 cycles per second or Hz), to Alpha (8-13Hz) -- meditation, Theta (4-8Hz) -- deep relaxation and dreaming, and Delta (.5-4Hz) -- slow wave or dreamless sleep.

Binaural beats between 1 and 30 Hz are alleged to create the same brainwave pattern that one would experience during meditation. When you listen to a sound with a certain frequency, your brain waves will synchronize with that frequency. The theory is that binaural beats can help create the frequency needed for your brain to create the same waves commonly experienced during a meditation practice. The use of binaural beats in this way is sometimes called brainwave entrainment technology.

Because the brain filters and interprets reality in a split-brained way, we tend to see things as separate and opposed, rather than as connected and part of the oneness spoken of by the great spiritual teachers (and, in the last few decades, by quantum mechanical physicists). Thus, at a deep level, the dual structure of our brain, in conjunction with brain lateralization, predisposes us to see and experience ourselves as separate from, and often in opposition to, the rest of the world—instead of experiencing the elegant interconnectedness between us and everything else. Our childhood associations and programming build on this inborn tendency by training us to seek this and avoid that, to move toward pleasure and away from pain, to do good and not bad, and so on. The greater the lateralization in the brain, the greater the feelings of separation—and the greater the feelings of separation, the greater the fear, stress, anxiety, and isolation.

It may be that you had the volume too loud, but I would expect you to hear the effects of that straight after you’ve stopped listening, not on a day you haven’t used them. It might be something similar to muscle memory, where you suddenly remembered the sound and sensations it gives you as if you were hearing it again. I don’t know how long you’ve been using this type of thing for, but maybe it’s something that will settle down and disappear once you become more accustomed to the sound.
Sleep issues are becoming much more of a common problem. I think it's great to look at alternative ways to help with insomnia and other sleep related issues, especially when they don't involve the need to take medication. Something proved to be effective is 'Sleepstation' a UK based organisation who use CBT techniques to cure insomnia. Their online sleep therapy course is brilliant and very convenient as it's delivered online. Their website is definitely worth a look if you're having sleep issues
How does brainwave entrainment work? Consistent, precisely engineered audio frequencies in the form of binaural beats cause the brain’s frequencies to match the stimulus. Your brain perceives two beats with slightly different frequencies (which are inaudible to the ear) through your headphones. It takes the difference between the two, and matches its own frequency to it. This is called the “frequency following” response.
Just my FIRST session I felt like I successfully achieved a theta state of meditation….I came out of it feeling extraordinarily renewed and with this profound insight of “everything is going to be ok”….this was all from my FIRST session. I cant wait to continue this on a regular basis to see where it leads….one day I hope to achieve the deeper delta states…
Completely free of spoken words, this program delivers a unique combination of Alpha, Beta, Theta and Delta binaural beats that produce an extraordinary “mind-awake/body-asleep” state through brainwave entrainment. Negative thoughts are dramatically swept away by brilliant flashes of insight and understanding as you experience untold depths of inner peace.
At any rate, I am enjoying the product immensely. I’m keeping a journal in which I’m recording my thoughts & observations as well as memory and cognition scores just as a sort of completely unscientific pet project, out of curiosity. So far, I’ve benefited from being better rested and more focused as a result of your product and that alone is worth the price of admission but I hope to be able to show that over an extended period of time, EquiSync can also improve working memory, cognition, &etc. I’ll be sure to share the data I collect with you if I get anything of statistical significance.

Entrainment is a phenomenon seen is a wide variety of different natural circumstance. In the field of chronobiology, the study of biological rhythms in living organisms, entrainment is the synchronization of a circadian rhythm with the rhythm of an external pattern, such as the synchronizing of women’s menstrual cycles with the phases of the moon or with one another in a group.
While originally brainwave entrainment was achieved by using pure tones of sound, it is now possible to take these tones and blend them with music, rhythms, and natural sounds, such as the sounds of flowing water, bird sounds, or waves lapping on a beach, creating extended tracts of varied and intriguing brainwave entrainment music for everyday use.
People with a past history of epilepsy or seizures should NOT use brainwave entrainment. Those with heart disorders or taking mood-altering pharmaceutical drugs should consult a doctor before trying. Also, some of the frequencies within the videos may make you feel sleepy. As a good practice, please do not listen whilst you are operating machinery or vehicles or carrying out any responsible duties.
Our Instrumental Music includes guitar music, relaxing piano music and flute music. Our instrumental music can be used for relaxation, study, meditation and stress relief. We like to use many different instruments and cultural sounds to add a range of unique music this includes - African Music, Tibetan Music, Asian Music, Indian Music, American Music, South American Music, Spanish Music, European Music, Chinese Music, Arabic Music, Australian Music, Native American Music, Aboriginal Music, African Tribal Music, Eastern European Music

In addition to potentially boosting sleep-promoting hormones, binaural beats may also reduce our perceptions of pain. A 2017 study found binaural beats used in combination with visual stimulation led to reductions in patients’ perception of acute pain. Other recent research showed binaural beats helped improve pain perception in patients with chronic pain.
While visual entrainment is more powerful than audio alone for inducing desired brainwave states, more caution is needed when using visual methods. Between 0.3 and 3 percent of the population is susceptible to having seizures from flickering light stimulation, and for other people, flickering visual stimuli simply makes them uncomfortable. People with epilepsy have a greater chance of having a seizure from exposure to flickering light stimulation.
Sit in easy pose or posture with a straight spine. Bring arms comfortably to the sides of the body with the elbows bent. Hands in fists with the thumb over the last three fingers, facing forward. Forefinger or Jupiter finger up straight. Hold the Jupiter finger very straight, tight and stable, without tensing the rest of the arms and body. The forearms should be perpendicular to the ground. During the meditation check the position and move the elbows forward as needed to maintain the position.
There isn’t really a one-size-fits-all track or frequency range which is right for all kids while doing homework. So that does make it difficult to recommend one thing in particular, and why I have a number of tracks for studying and focus. If they have already learnt and understood the information, but are just trying to commit it to memory for a test, then I would recommend an alpha track, like the Memorization Study Aid product I have with the 10.4Hz frequency you referred to. If they are still trying to fully understand what is being taught in a workbook, then I would recommend a track that is mainly beta frequencies, like my Study Focus tracks. In the middle, I have a number of tracks which use a combination of beta and alpha wave frequencies, like Study Booster, Study Enhancer and Cognition Enhancer. The last 3 use similar frequencies but deliver the tones and brainwave entrainment effects in different ways. As we are all wired a little differently it does sometimes take a bit of trial and error, to see what method or frequency range works best for the individual. These types of tracks are made for a general audience. In an ideal world, you would hook up to an EEG and see in real time exactly what a person responds to best, depending on the goal and current state of mind.
The most common way to use a brainwave entrainment is for a short-term benefit, to help guide your brain into a particular mental state at the time you need it.  In a similar way to how you might take a sleeping pill before bed to help you get to sleep, or maybe drink some coffee or an energy drink to help wake you up and give you a boost of energy.
Have only used this for a couple of nights, but it does do the trick of staying or returning to sleep if you have it on repeat or in a longer playlist line up. I would recommend it. I would say that however, you need to try it for a least a week, as the initial getting used to it and not fighting the rhythm may occur - so at least give it a chance.
When blended with musical sounds, brainwave entrainment frequencies induce specific states of mind, which are the result of those brainwaves, delivering them in pleasing and relaxing audio tracts for use with and without stereo headphones. For example, alpha and theta waves, because they exist at the borders between conscious and unconscious thought, are especially rich and useful for tapping into and stimulating subconscious processes.
Binaural beats were first discovered in 1839. The effects of using audio instead of light for brainwave entrainment were noted in 1959. Oster’s research paper in 1973 brought attention to the use of binaural beats in a medical setting and this inspired a range of studies in the 1980s indicating very positive findings. The effects of brainwave entrainment using binaural beats has become of a hot topic of research ever since but despite their reported successes, they have never quite shook off the sometimes negative connotations of being an “alternative medicine”.
3. Alpha State: (9 — 13Hz) Brain waves start to slow down out of thinking mind. We feel more calm, peaceful and grounded. We often find ourselves in an “alpha state” after a yoga class, a walk in the woods, a pleasurable sexual encounter or during any activity that helps relax the body and mind. We are lucid, reflective, have a slightly diffused awareness. The hemispheres of the brain are more balanced (neural integration).
Binaural beats require two separate tones from two sources that are combined inside the listener’s brain to form the target tone. The lower frequency sound is called the carrier tone, and it is combined with a higher frequency sound known as the offset tone. Because of this, binaural beats must be listened to with stereo headphones or the effect is lost. Binaural beats create a hypnotic effect, but they are not the most effective tool for brainwave entrainment, and binaural beats are often ineffective for people with hearing loss.
This is something which will come to you with practice. For instance you may feel an energy around and inside you like you have shifted dimensions but are still there. Instead of thinking this is God, the Zone or whatever, think of this as your soul, you essence, your expanded pure light being. In this way you will begin to train yourself to find your identity in your expanded being and your internal identity. This is what we want - to let go of the idea that we are a limited ego.

Brainwave entrainment is also known as brainwave synchronization.  According to Wikipedia  brainwave entrainment is “any practice that aims to cause brainwave frequencies to fall into step with a periodic stimulus having a frequency corresponding to the intended brain-state (for example, to induce sleep), usually attempted with the use of specialized software.”
For example, if a 530 Hz pure tone is presented to a subject's right ear, while a 520 Hz pure tone is presented to the subject's left ear, the listener will perceive the auditory illusion of a third tone, in addition to the two pure-tones presented to each ear. The third sound is called a binaural beat, and in this example would have a perceived pitch correlating to a frequency of 10 Hz, that being the difference between the 530 Hz and 520 Hz pure tones presented to each ear.