Isochronic tones work by influencing your brainwave activity and they can’t directly affect the body. That said, the brain does control the body, so sensations and feelings can sometimes be felt in the body after stimulating your brainwave activity. Some people who are new listeners of this type of audio can sometimes feel tingling sensations in their body. Not everyone feels this and these sensations usually stop once you get more used to using the audios. Isochronic tones are considered as a safe technology. However, sometimes they can leave you feeling temporarily fatigued, especially if you listen to them for an extended period (hours) when you first start using them. If you felt fatigued, I would recommend using them for a much shorter period while you are getting used to them and ensure you are well-hydrated.
I was recently asked a question by my nephew, regarding binaural beats. Because of my involvement with meditation and relaxation techniques, he felt comfortable asking about the safety of it and what it was, exactly. I provided him with some information that I felt would assist him in his choice, as to whether or not to listen, and I decided to do a little more research on the subject, in order to better educate myself. I know a little about the topic, but I wanted to know more about it.
Sleep is something that many people take for granted, but since it takes up about one-third of our lives, it’s worth considering carefully. Besides the obvious benefit of providing time for cell regeneration and repair, eight hours of regular, sound sleep sets you up for optimal functioning of mind and body. It strengthens your immune system, improves your mood, and sharpens your alertness and powers of attention. Getting sufficient sleep lowers your risk of high blood pressure, heart disease, obesity, and diabetes, and it makes you less susceptible to accidents. 
In addition, Western culture reinforces thought and communication styles associated with the left brain hemisphere, which controls logic, language, and linear thinking in a majority of people, as opposed to the right hemisphere which controls brain centers for emotional, intuitive, creative, and non-linear thought processes. Note that a significant minority of people has the opposite hemispheric dominance than the majority of people.
…I got curious about the Equisync II CDs and it was the 2nd track that started giving me some body signs that revealed me I was in the alpha state. I never practiced meditation before, however, I follow the Gurdjieff and Ouspensky teachings which, if you are not aware, tell us how to do quite the same thing as meditation in our everyday lives while performing our daily tasks. I also believe that Equisync II was more appropriate for me because my life is also dedicated to collective causes, my personal life is totally under control, but your CDs were able to relieve my severe depression after only 3 days of practicing, my chronic insomnia condition which had been lasting for over 27 years seemed to be finally healed. I am truly amazed, really.
Theta: This brainwave pattern is associated with deep relaxation and with some stages of sleep, including the lighter stages of non-REM (NREM) sleep. REM sleep itself is mostly composed of beta wave and other activity that’s similar to an alert, waking brain. Deep meditation produces theta waves, which are slower and lower frequency (between 5-8 hertz) than Alpha waves. That murky barrier between sleep and wakefulness, when you’re drifting in and out of sleep, and your thoughts feel dreamlike and difficult to remember? That’s a theta-dominant state of consciousness.
But the notion of changing brain waves is a very appealing one, from a marketing stand point. People can visualize brain waves and we like synchrony. Also, in the computer age, we understand the notion of “programming.” We also have been prepped for the future by movies such as The Matrix, where people could master Kung Fu in minutes by simply “downloading” the knowledge. This gives the whole notion a superficial plausibility. But the science just isn’t there.
However, yoga and meditation take time to learn and master, and until the student becomes proficient, progress can be slow and frustrating, leading many people to abandon the effort before they see the benefits. Brainwave entrainment has the potential for helping a person enter the relaxing and rejuvenating mind-states brought about by yoga and meditation without the learning curve and time needed for mastering these other techniques. Brainwave entrainment may even facilitate learning other mindfulness methods by helping a person achieve success faster and more reliably. 
Meditation Begins • Mind Chatter Slows Down • Great For Learning & Studying • Creative Ideas Flow • Reverse Brain’s Aging • Habits, Fears, Phobias Melt Away • Calm & Peaceful • First Layer Of Subconscious Mind • Gateway To Deeper Mental States • Advanced Focus • Relaxation Begins • Serotonin • Endorphins • Good For Anxiety, Depression, Stress, Panic • Mind Power • Happiness • Confidence

I am fortunate to be working with Deepak Chopra, M.D., and Dr. Rudy Tanzi, co-authors of the bestselling book Super Brain, on a technology called Brain Wave Entrainment. Deepak is very well known, but Rudy is an amazingly interesting person as well. He is the Kennedy Professor of Neurology at Harvard Medical School and Vice-Chair of Neurology at Mass General Hospital. Rudy co-discovered three of the four original Alzheimer's genes and today runs the Alzheimer's Genome Project. He also plays the keyboards, including, at times, for Aerosmith. He is kind of a real life "Buckaroo Banzai."
A therapy that slows brainwave activity, helping to produce low frequency waves, is likely to aid relaxation and sleep. But it’s not only lowering brainwave frequency that binaural beats may offer to sleep and relaxation. A small study (19 people) has found that exposure to binaural beats is associated with changes to three hormones important to sleep and well being:
Studies have shown binaural beats may affect levels of dopamine, a hormone that plays a broad role in cognition and a particular role in creative thinking. This has scientists examining the possibility that binaural beats can be used to stimulate creativity. (If you’re looking to be more creative and innovative in your thinking, keep in mind that sleep itself is a powerful tool!)
Theta brainwaves are next highest in frequency above delta and are especially important for many people using brainwave entrainment and meditation because theta waves are at a threshold, forming a link between wakefulness and the subconscious mind. Theta waves bridge between our awake self and the creative and insightful understandings from below our conscious awareness, and while they are not common in awake adults, they are normative for children under 13 years old. 
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.
Our relaxing music is perfect for Deepak Chopra Meditations, Buddhist meditation, Zen meditation, Mindfulness meditation, Kundalini meditation, Qi Gong Meditation, Zazen Meditation and more. Our music is influenced by Japanese meditation music, Indian meditation music, Tibetan music and Shamanic music. Our instrumental music has been designed to encourage and enhance relaxation, meditation, brain function and concentration, spa and massage therapy, and healing music therapy. In addition, we use binaural beats (Delta, Alpha and Theta Waves) to naturally reach a state of relaxation perfect for concentration, meditation or deep sleep. Our music playlists are perfect for your daily meditation and relaxation. Our music videos use soundscapes such as nature sounds, animals, oceans, rain sounds, thunder sounds and many more).
A binaureal beat is created by playing a different tone in each ear, and the interference pattern between the slightly differing frequencies creates the illusion of a beat. It's intended to be heard through headphones, so there's no cross-channel bleed across both ears. Listen to this, I'll play a simple binaural beat, and I'll slide the pan control back and forth from one ear to the other. You can see that there isn't actually any beat, it's just an acoustic illusion:
×