Brain Wave Entrainment is any procedure that causes one's brainwave frequencies to synchronize with a periodic stimulus (sound, vibration or light) having a frequency corresponding to the intended brain-state (for example, to induce a trance, dreams, sleep or relaxation.) It is also called the Flicker-response because of how staring at a campfire or the flickering of a burning candle can lull you into a state of calmness and serenity. There was an extensive article on this phenomenon by Gerard Oster in Scientific American in 1973. It may sound novel, but in many ways, this is old tech.
Deep relaxation is a major benefit resulting from the brain’s cortical frequency following response. By selecting the desired rate the brain, via the frequency following response, will tend to mimic the rate it is exposed to and thus enter that brainwave state. This helps to explain why this technology can produce benefits commonly found with meditation. One of the most valuable benefits of consistent  brainwave entrainment is that we are able to experience and recognize the various states of consciousness. With practice we can learn how to re-create these states.
Insomnia and PTSD for most of my life are real bears that I wrestle with every night. A brain neural-therapist (for lack of a better description) said that this kind of sound recording may help. It is not music. When I remember to play the disc, I fall asleep within the first 5-8 minutes. One day I played the disc while cleaning and I was very surprised to hear how much of the recording I never recall hearing before. That's why I know how long it takes to fall asleep.
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.
Isochronic tones have only been proven to have an effect while you are listening to them, that’s why you won’t find me claiming anywhere that there are potentially positive long-term effects. Once the tones stop, your brainwaves are no longer being stimulated by the sound and so they stop being in sync with the tone frequency. For you to think you are still feeling the effects after all this time and from such a short time listening to them, I think it may be linked to anxiety. I know that some people who are new to this type of thing can build up a strong feeling of anxiety, after worrying about the potential effects brought on by fear of the unknown. I suspect the problem may be psychological with you worrying about the potential effects and keep repeating the experience from memory in your head. When you keep going over the same thing in your head like that and worrying about it, it’s easy to then spot other potential side-effects like how your nostrils and body temp is feeling, then making links back to that experience and labelling that as the reason. I think the best way to overcome this is to realise that the side-effects you are mentioning are completely unrelated, so there is nothing to worry about. These tracks are literally listened to for millions of hours a month on YouTube across loads of channels. If the effects lasted for a long time people would just listen for 5 minutes and come back in a couple of weeks. But people keep coming back to listen because that’s the only way to feel the benefit and effects…while you are listening to them. If you are unable to stop thinking and worrying about this on our own, I recommend that you speak to your doctor about it or a specialist in dealing with anxiety issues. I hope that helps.
This is good to understand because this is another area where people can make huge promises that may or may not be true. Even in this realm, there is a level of practicality that can be followed. Even meditating at the rate of a super-human monk is not going to “magically solve all your problems”. This technology cannot pick negative beliefs out of your head and implant positive ones just by influencing your brainwaves. It cannot just make you a different person.
Because EquiSync®'s audio-based brainwave entrainment technology guides your brainwaves into various states of meditation, it helps to understand how alpha, theta, and delta waves contribute to your state of consciousness. The two charts on this page illustrate the basic benefits of each brainwave state as well as the targeting of the EquiSync programs 1, 2, & 3.

A common element in recordings incorporating alpha and theta frequencies is a steady but barely perceptible rhythm of the frequencies themselves. This subtle and calming pulse mixes with sounds of gentle breezes, distant bird songs, and the slow progression of deep synth notes. Underneath this, below the audible sounds at sub 16 hertz levels, other frequencies intermingle, deepening the merging of conscious and unconscious mind.
So my question is: Why? When I read it, I had a bit of a fear of brain aneurysms. Therefore, 1. could someone contact me to tell me why use of your product shouldn’t continue past 2 hours? [I probably won’t heed the reason unless it’s a life or death warning: I love this product that much!] 2. Please feel free to post my letter in your testimonials, if you ever decide to post such customer comments.
Entrainment is a term originally derived from complex systems theory, and denotes the way that two or more independent, autonomous oscillators with differing rhythms or frequencies, when situated in a context and at a proximity where they can interact for long enough, influence each other mutually, to a degree dependent on coupling force, such that they adjust until both oscillate with the same frequency. Examples include the mechanical entrainment or cyclic synchronization of two electric clothes dryers placed in close proximity, and the biological entrainment evident in the synchronized illumination of fireflies.[13]