If mind-consciousness is not the brain, why then does science relate states of consciousness and mental functioning to Brainwave frequencies? And how is it that audio with embedded binaural beats alters brain waves? The first question can be answered in terms of instrumentation. There is no objective way to measure mind or consciousness with an instrument. Mind-consciousness appears to be a field phenomenon which interfaces with the body and the neurological structures of the brain (Hunt, 1995). One cannot measure this field directly with current instrumentation. On the other hand, the electrical potentials of brain waves can be measured and easily quantified. Contemporary science likes things that can be measured and quantified. The problem here lies in oversimplification of the observations. EEG patterns measured on the cortex are the result of electro-neurological activity of the brain. But the brain's electro-neurological activity is not mind-consciousness. EEG measurements then are only an indirect means of assessing the mind-consciousness interface with the neurological structures of the brain. As crude as this may seem, the EEG has been a reliable way for researchers to estimate states of consciousness based on the relative proportions of EEG frequencies. Stated another way, certain EEG patterns have been historically associated with specific states of consciousness. It is reasonable to assume, given the current EEG literature, that if a specific EEG pattern emerges it is probably accompanied by a particular state of consciousness.  
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 1956, the famous neuroscientist W. Gray Walter published the results of studying thousands of test subjects using photic stimulation, showing their change in mental and emotional states. He also learned that photic stimulation not only altered brainwaves, but that these changes were occurring in areas of the brain outside of vision. In Walter’s words:
Brainwave entrainment music can be used almost anywhere and anytime, making this mood and self-improvement method versatile and flexible enough to do at work, while traveling, or at other times during the day. When used in the workplace during short rest periods, brainwave entrainment techniques can enhance concentration, communication, and work productivity.
a concise P.S. I was in a horrible car accident when I was 18 and had to learn to read and write and walk and talk all over again. It was long ago and I’m pretty well over it, but such an injury has lifetime repercussions. The neurological damage sustained causes my left arm to shake uncontrollably anytime I use it in a situation requiring precise coordination. From simply listening to the demo, the shake [though not disappearing completely in the last 2 months] has lessened dramatically. I had been wondering for years what kind of neurological exercises I could undergo to help it…
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.
I first became aware of brainwave meditation programs  and brain waves when researching alternative methods for treating the bipolar disorder I had been unsuccessfully living with my entire adult life. I eventually learned a method of releasing difficult emotions on the spot, which I then practiced extensively, and consequently found it easier and even desirable to meditate for fairly lengthy periods of time. Though I took up meditation as a serious daily practice and experienced many undeniable benefits, I nonetheless intermittently experienced life-debilitating bouts of mania and severe depression, often resulting in chaotic mixed states and an inability to maintain daily social functions. During these times, it became nearly impossible to sit in meditation.
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.
When you play a tone with a slightly different frequency into your left and right ear — say, 200 hertz (Hz) in one and 210 Hz in the other — they travel separately to your inferior colliculus, the part of your brain that gathers auditory input. There, the tones “squelch” together into a so-called “beat” at a perceived new frequency. (In this case, it would be 10 Hz.)
From a brainwave entrainment effectiveness perspective, it’s my understanding that the response from isochronic tones stimulation starts to diminish over 30Hz and that 40Hz is about the limit for using them. So from what I’ve read on the topic a 100Hz beat wouldn’t work, probably because it’s too fast for the brain to process and synchronise with it.
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).

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.
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. 
“In order to get into a flow state, you have to calm a part of the brain, the posterior cingulate cortex, which is the source of what brain scientists call the default state, which is the non-focused state,” says Harris. “At any rate, it turns out that Holosync [binaural beats], when you listen to it, [calms that part of the brain] and so does traditional meditation. It’s just Holosync does it faster and more easily and more effortlessly. It turns down the posterior cingulate cortex and it enhances the other part of the brain that, when it’s enhanced, you can easily go into a flow state.”
Please note: When you take one earphone out, move it as far away from your ear as possible. With some headphones you may still be able to hear the pulsating sound if the removed headphone is still fairly close to your ear; this is because your brain can still detect the frequency vibration coming from the headphone. In addition, push the earphone that’s still on your ear tightly to your ear, while moving the other earphone as far away as possible.