“Stress and sleepless nights are closely linked,” Buenaver says. “If you’re in pain, tend to worry, or are coping with a difficult situation in your life, you may have more stress hormones than usual circulating in your body. A poor night’s sleep adds even more. And those hormones may never be fully broken down. It’s like running an engine in fifth gear all the time.”
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.

Theta waves have another interesting characteristic. The Earth has a measurable resonance of 7.83 hertz known as the Schumann resonance. Because the Schumann resonance is a constant background frequency surrounding all life, it may play a special role in biological activity. The Schumann resonance frequency falls within the range of theta brainwaves and may have something to do with why these brainwave frequencies are so powerful. 
2. The other thing you cannot afford to do is evaluate whether or not a technique is having an effect based upon having (or not having) any of those superficial, irrelevant, distracting phenomena discussed above, like face flushing, seeing light swirls, having sensations of this, that or the other thing, etc. Those kinds of phenomena will just lead you down the wrong path and steer you away from the true benefits of meditation. If you’ve already fallen into the trap of this sort of conditioning, using something like the Release Technique, the Sedona Method, or even EFT can be helpful in breaking established conditioned associations.
This can help develop the ability to see energy fields around people and in nature, and it will also make it much easier to stay awake during your meditations. When your eyes begin to close, you simply have to open them back up again. Doing the meditations with your eyes open is a serious step up in exercising your brain, so go slow with that technique at first.
Beware simple answers to complex problems, or easy methods for accomplishing difficult goals. If you combine this maxim with the advice to be skeptical of any claims that are being made in order to sell you something – then ironically you have a simple method (perhaps I should call it an “elegant” method) for protecting yourself from most scams and cons. Actually the application of this combination of maxims can be complex, but what it does do is trigger doubt and skeptical analysis. (And to be clear I am not saying that all simple solutions must be wrong – you should just beware them, meaning your skeptical senses should be tingling.)
This is an extreme example, naturally, but the idea holds true even in situations that are not as extreme. This ties in very closely with Point #4 above. When you’re wishing to combine meditation and brainwave entrainment, if you’re practicing a meditation technique but not really paying attention to what you’re doing, or perhaps you are performing the technique wrong, whilst allowing your mind to drift off to wherever it takes you, it should come as no surprise that the entrainment track is not helping you achieve a state of meditation. That’s because in fact you aren’t really trying to enter meditation or because you’re specifically engaging in activities that prevent you from getting there.
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.
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.
Theta brainwaves in the frequency range of 6 to 9 hertz are known as thalpha waves because of their proximity to alpha waves. They are seen during states of high suggestibility, during hypnosis, and during paranormal experience and are also connected to an increase in human growth hormone (HGH) levels and higher blood flow to the brain. Theta brainwaves sit between the realms of the subconscious and conscious mind, making them an especially useful brainwave state for developing creative thinking, working through emotional problems, and integrating subconscious and conscious experience. 

Cognitive behavioral therapy (CBT) is a type of therapeutic practice that has been proven to lower anxiety, stress and multiple disorders — including addiction, eating disorders, insomnia and depression. Knowing that at least 50 percent of the time experiencing a mental disorder is due mostly to chronic, untreated stress reactions, therapists use CBT to train all types of people to better react to situations that are stressful.
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.

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. 
So to summarize their claim, they're saying that entrainment means that a binaural beat will cause your brain's electroencephalogram to match the pattern of the phantom beat. Well, if it did, entrainment certainly doesn't apply and would not be part of the equation, so we can scratch that off the list. But it doesn't make the claimed observation wrong. We do know that certain electroencephalogram waveforms are often associated with certain kinds of activity. For example, physical activity or REM sleep often produces an electroencephalogram with a sine wave of between 4 and 8 Hz, which we term a theta pattern. Waking relaxation with eyes closed often produces a pattern from 8 to 12 Hz, which is called an alpha pattern. There are only a few characterized patterns, and pretty general descriptions of what kinds of activities go with them. The claim made by the binaural beat sellers depends on much more granular and specific matches. For example, the claim that a binaural beat with a frequency of X produces the same effect in your brain as Vicodin is wholly implausible. Such claims presume that we know the exact frequency of the electroencephalogram in each of these desired conditions, and the fact is that brain waves don't work that way. It is wholly and absolutely implausible to say that desired brain condition X will occur if we get your EEG to read exactly X Hz.
The Delta brainwave is experienced by us every night in dreamless sleep. It is also experienced by advanced yogis and monks who can enter the Delta frequency during deep meditation. This frequency assists in both emotional and physical healing, as well as enhanced immune functioning, significant stress reduction, and even anti-aging benefits. The Delta frequency is a terrific way to experience deep repair on the physical, emotional, and psychological levels.
They are not beyond what is “normal” but for most of us they are outside of what is “typical”. Whether we consciously seek them or not, somewhere in the back of our minds we hold beliefs that because meditation and brainwave entrainment are beyond our usual set of experiences, then the evidence that they are having some sort of effect on us must also be outside of our normal range of experiences.
... Audio visual stimulation effects people on two levels: Budzynski (2001) reports significant improvement of mental capabilities after AVS in 75-year old male. Cruceanu and Rotarescu (2013) proved that the exposure to 30-minutes of audio-visual stimulation with the frequency of 10,2 Hz significantly improves cognitive skills. Based on their research, authors claim that people need to be exposed to AVS at least for 20 minutes in order to achieve positive effects. ...
Controlled or pre/post studies of the effects of BWE using auditory or visual stimulation were eligible for inclusion, provided pulses of light or tone were delivered at frequencies hypothesised to have a beneficial effect or in line with a protocol addressing clinical outcomes. Studies were required to report clinical or psychological outcomes (measured using standard methods or as deemed appropriate by peer review) and to report statistical analysis. Studies of outcomes such as electroencephalogram (EEG) response or neurotransmitter levels were not eligible. Case studies were excluded.