way of describing it—at both theta brainwave frequencies. And then there are also 40-Hz gamma frequencies, the frequency that came through a lot when the Dalai Lama sent some Buddhist monks to have their brain waves studied as they were meditating and doing loving-kindness practices. Gamma is associated both with heightened awareness and also with loving-kindness practices, metta practices.
Brainwave entrainment is a field of study and endeavor founded in the same physiological and psychological processes that make music, drumming, and chanting so powerful as methods for transforming the mind and spirit and aiding in healing of the body. These processes involve how the electrical energy in our brains synchronizes with sounds and visual stimuli, producing a particular brainwave frequency and its associated mental states. 
The brain is composed of millions of specialized cells called neurons. Neurons send signals to other neurons using electro-chemical messengers called neuro-transmitters that attach to receiving sites located on the neurons themselves. There is a space between the end of the neuron and the receptor called the synaptic gap. As neuro-transmitter chemicals move across this gap, a small electrical charge is created. 
Our Reiki Music and Zen Music is ideal for Reiki healing sessions, and encouraging a state of Zen. Let the calming, subtle sounds take you to a higher state of consciousness, and allow you to give and receive powerful Reiki vibrations. Our Chakra Music use special formulated frequencies for each stage of your chakra. We have individual tracks to unlock your Root Chakra, Sacral Chakra, Solar Plexus Chakra, Heart Chakra, Throat Chakra, Third Eye Chakra and the Crown Chakra. Chakra Music for Chakra Healing, Chakra Balancing, Chakravakem, Chakra Guided Meditations and anything Chakra
The Neuro Programmer website, as is typical, is full of testimonials and vague references to research. I tried to track down the research they referenced, but could not find anything published or peer-reviewed by the authors named or on the subjects indicated. For example, they cite one study by Thomas Budzynski, but the only thing published by him that is listed on Pub Med is a small study on biofeedback published in 1969. The 1999 study they reference is not listed. Also – Budzynski has connections to another company – Theta Technologies – which sells similar technology.  (The exact nature of his connection is not clear, he was at least a consultant. He is also listed as the director of research for another company, Synchromed, LLC.)  This looks like just another in-house worthless study to support the marketing of a product.
Thanks for the coupons, I had originally looked into these cd’s after my doctor recommended them, but my mom wound up buying them for me for Christmas (she didn’t know about the coupons I had!) Anyway just listened to Equisync II today for the first time, I was in such a state as to where I didn’t know if I’d fallen asleep or not! I hadn’t but was in such an amazing place.
So using the example track above, the right ear is sent a 20Hz beat, compared to a 10Hz beat in the left ear.  As the right ear receives the higher frequency of beat, this works to increase the speed of the ‘left' brain hemisphere, which can be helpful for people with conditions like ADD, who are often found to have an abundance of slow wave activity in the left brain.
There is a solution, which, although you may not have heard about it, has been around (and scientifically tested!) for decades now. By using binaural beats, you can ease your brain from its active state into a more restful state simply by listening to a different frequency wavelengths of sound in each ear. Because two different wavelengths are entering through two different entrances (your ears), that difference is perceived as a “beat” (though it may sound like a warble to some) that resonates at the frequency equal to the difference. The brain will entrain (match) itself to the beat produced by the difference in wavelengths. If the difference between the two wavelengths is less than seven hertz, your brain will fall into a state of deep relaxation, also known at the theta range.
You can experiment with the length of time you listen to the binaural beats to find out what works for you. For example, if you’re experiencing high levels of anxiety or stress, you may want to listen to the audio for a full hour or longer. Remember, you must use headphones for binaural beats to work. You may also want to listen with your eyes closed.
♥ I'm a tired law student always looking for a study boost. I like to put on the Alpha waves and mix this with classical music for research and writing. The "beats" help to drive the music and add a feeling of focus and energy even during slower/softer passages. If you get the levels matched properly, you never even hear them. Throw in a cup of coffee and you'll be ready to save the world. Cheers!
Robert Monroe, a radio producer and executive published a popular book called Journeys Out of the Body about his out-of-body experiences when using brainwave entrainment. He later founded an original brainwave entrainment audio company, Hemi Sync. In 1981, the book Mega Brain by Michael Hutchison brought brainwave entrainment information, techniques, and terminology into the popular press.
Hi EJ, at the moment, there hasn’t been any research to give an indication of how long you should or shouldn’t listen for. Over time, I’ve seen people use my tracks for longer and longer. I started off providing 30-minute study tracks, but through demand, I extended them to 3-hours. I know from the many thousands of comments I’ve had on YouTube that a large number of people play those 3-hour tracks on repeat, or listen to different ones, one after the other throughout the day. I’ve also seen apps where you can play tracks like mine on continuous repeat. So it’s common for people to listen to them all day while they are studying.

Synchronized brain waves have long been associated with meditative and hypnogogic states, and audio with embedded binaural beats has the ability to induce and improve such states of consciousness. The reason for this is physiological. Each ear is "hardwired" (so to speak) to both hemispheres of the brain (Rosenzweig, 1961). Each hemisphere has its own olivary nucleus (sound-processing center) which receives signals from each ear. In keeping with this physiological structure, when a binaural beat is perceived there are actually two standing waves of equal amplitude and frequency present, one in each hemisphere. So, there are two separate standing waves entraining portions of each hemisphere to the same frequency. The binaural beats appear to contribute to the hemispheric synchronization evidenced in meditative and hypnogogic states of consciousness. Brain function is also enhanced through the increase of cross-collosal communication between the left and right hemispheres of the brain.
way of describing it—at both theta brainwave frequencies. And then there are also 40-Hz gamma frequencies, the frequency that came through a lot when the Dalai Lama sent some Buddhist monks to have their brain waves studied as they were meditating and doing loving-kindness practices. Gamma is associated both with heightened awareness and also with loving-kindness practices, metta practices.
Slightly higher-frequency entrainment can lead to hyper suggestive states of consciousness. Still higher-frequency EEG states are associated with alert and focused mental activity needed for the optimal performance of many tasks. Perceived reality changes depending on the state of consciousness of the perceiver (Tart, 1975). Some states of consciousness provide limited views of reality, while others provide an expanded awareness of reality. For the most part, states of consciousness change in response to the ever-changing internal environment and surrounding stimulation. For example, states of consciousness are subject to influences like drugs and circadian and ultradian rhythms (Rossi, 1986; Shannahoff-Khalsa, 1991; Webb & Dube, 1981). Specific states of consciousness can also be learned as adaptive behaviors to demanding circumstances (Green and Green, 1986).  

I received my order on Mon. and have done 3 or 4 sessions of Equisync I. I just wanted to say I can already notice a difference in myself. I am much calmer and more clear thinking already in just 2 days. I don’t think it’s my mind playing tricks on me. Is this a common occurrence? Your product is great I can’t wait to try Equisync II and Equisync III.
"Wow! I have been doing this Awakening Kundalini guided meditation every morning for about two weeks now. I am a yoga teacher and I have never experienced energy like this before! Every morning, I feel a surge and abundance of endless vital energy nourish my mind, body, and soul. The sounds, theta waves and guidance are perfectly combined to gently awaken the sleeping serpent confirmed by the exquisite sensations experienced. "  --Katarine
Most of these websites give some brief explanation of entrainment. The example you hear most often is that of Dutch polymath Christiaan Huygens, who in 1665, hung two pendulum clocks next to each other on a wall. He noticed that the pendulums eventually matched each others' frequency, but always in antiphase, opposite to each other, as if canceling each other out. He'd try disturbing one or setting them in sync, but they'd always return to the same antiphase synchronization. Huygen's experience is widely touted on binaural beat websites as a demonstration of how systems can become spiritually connected through some energy field. However, they misunderstand what happened, and have not read the full story. Huygens also tried taking one clock off the wall, and as soon as they were no longer physically connected to one another via the actual wall, the effect disappeared. It was not the proximity of the clocks to one another that created the entrainment; it was their physical, mechanical connection to one another. As each pendulum swung it imparted an infinitesimal equal and opposite reaction to the wall itself. With two clocks on the wall, the system naturally sought the lowest energy level, according to the laws of thermodynamics; and both pendulums would thus swing exactly counter to each other, minimizing the system's total energy.