The activity of neurons generate electric currents; and the synchronous action of neural ensembles in the cerebral cortex, comprising large numbers of neurons, produce macroscopic oscillations. These phenomena can be monitored and graphically documented by an electroencephalogram (EEG). The electroencephalographic representations of those oscillations are typically denoted by the term 'brainwaves' in common parlance.[4][5]

All of this is entirely understandable, even somewhat predictable. Unfortunately, it quickly becomes counter-productive. Such experiences, while having a certain feeling of solidity to them, are largely the product of our desires and expectations. Did your face get flushed? One look in the mirror confirms it did. Was this caused by the entrainment? No, it was not. It was the result of what was sought after and what was expected or even hoped for.

Thanks for the reply. I am now clearer on ‘what’ is heard. Can you expand or point me in direction ..a bit more about ‘pitch frequency’ and frequency spoken about and what exactly is the difference ..and how we use the higher pitch frequencies to ‘hear’ or become aware of them? Would you only pick up the low freq on a EEG?. sorry for being pedantic still does not clear up split isochronics and possibly creating same situation as binaural beats..
Joe:             The Journey  soundscape took a lot of work. I wanted to bring in the very best of what I knew about brainwave entrainment and to make the best brainwave entrainment product—with the best entrainment technology—that I possibly could. So, there are all sorts of things going on in Journey  to provide a sound bed to support the experience of expansiveness and also communicate elements of the heart-based work I talked about earlier. (See part I of this interview, A Guide to Transpersonal Meditation.)
Gamma waves are the fastest brainwave frequency range. Gamma brain waves are believed to link and process information from all other parts of the brain. A high amount of gamma wave activity in the brain is associated with intelligence, compassion, focus and feelings of happiness. High levels of gamma brain waves have also been linked to improved memory and an increased sensitivity to sensory input. Low amounts of gamma brainwave activity have been linked to learning difficulties, poor memory and impaired mental processing.
Making time for connecting with the people around you, spending time outside and doing things you love with family, friends and your spouse are all stress relievers that are good for your health in many ways. Social connection is tied to longevity, since it helps people feel like they’re a part of something larger than themselves and helps give them perspective. Being outdoors has some similar effects, reminding people that they’re one piece of a much larger universe, lifting their moods and making it easier to get good sleep. (12)
There’s an aesthetic element to the music and there are a lot of drone-based sounds and time-stretched sounds, deep, rich bass sounds—there’s a spectrum of sounds within there—and what’s more, there’s a load of 3D processing that goes on to ensure that the mind doesn’t become habituated to them. There’s also a constant, subtle sense, a slow and gradual sense, of the sounds shifting around. And, there are layers of binaural beats.

In the 1980s, a researcher in Japan, Tsuyoshi Inouye described how light stimulation creates synchronization of brain hemispheres. Since then, other researchers have detailed the positive effects of hemispheric synchronization including a 1984 study by researcher Dr. Gene W. Brockopp stating that hemispheric synchronization resulted in improved intellectual functioning as well as improvements in long-term memory, and these effects are cumulative over time.

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).  
Most of our Royalty Free brainwave entrainment music uses an audio technology known as "binaural beats". These binaural beats are embedded in the music in order to bring about desirable changes in brainwave activity, thereby encouraging various states of relaxation, deep meditation or sleep. When played with headphones, you may be able to hear the binaural beats as a subtle pulsing sound beneath the music.
For many of us, relaxation means zoning out in front of the TV at the end of a stressful day. But this does little to reduce the damaging effects of stress. To effectively combat stress, we need to activate the body’s natural relaxation response. You can do this by practicing relaxation techniques such as deep breathing, meditation, rhythmic exercise, and yoga. Fitting these activities into your life can help reduce everyday stress, boost your energy and mood, and improve your mental and physical health.
Yoga involves a series of both moving and stationary poses, combined with deep breathing. As well as reducing anxiety and stress, yoga can also improve flexibility, strength, balance, and stamina. Since injuries can happen when yoga is practiced incorrectly, it’€™s best to learn by attending group classes, hiring a private teacher, or at least following video instructions. Once you’€™ve learned the basics, you can practice alone or with others, tailoring your practice as you see fit.
Just so, when you reach a state of meditation you don’t “keep digging”, so to speak. The hole has been dug. All that digging has done what it was meant to do. Once your technique has gotten you into meditation, STOP DIGGING! You’re there. If you keep digging you will frustrate your ability to remain in meditation for any significant period of time. Only resume your chosen technique if and when you slip out of the meditative state. If you’re human then you WILL slip out of that state again and again. Don’t worry about that. That’s how the process works for all of us mere mortals.
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.

A large dose of caffeine causes a short-term spike in blood pressure. It may also cause your hypothalamic-pituitary-adrenal axis to go into overdrive. Instead of coffee or energy drinks, try green tea. It has less than half the caffeine of coffee and contains healthy antioxidants, as well as theanine, an amino acid that has a calming effect on the nervous system.
Sensorimotor rhythm (SMR) is one final type of brainwave that has been studied. SMR, also known as low beta, is a type of brainwave, which occurs in the sensorimotor cortex, in the 12 to 15 hertz range when that area of the sensorimotor cortex is idle and immobile. The purpose of SMR brainwaves is not well understood, but some neurofeedback practitioners report training to increase SMR brainwaves can be beneficial for people with autism, epilepsy, ADD, insomnia, drug addiction, and as an aide to better manage stress.

It’s important to keep in mind; a person’s own experiences will be somewhat relative to their starting point. If you are a person who is completely stressed out, burned out, hanging on the ragged edge, experiencing total adrenal fatigue, and you’ve been at that point for awhile, then to you even a small degree of mental quiet and physical relaxation that meditation and brainwave entrainment bring will feel like a tsunami of relief.
While visual entrainment is more powerful than audio alone for inducing desired brainwave states, more caution is needed when using visual methods. Between 0.3 and 3 percent of the population is susceptible to having seizures from flickering light stimulation, and for other people, flickering visual stimuli simply makes them uncomfortable. People with epilepsy have a greater chance of having a seizure from exposure to flickering light stimulation.
Literally embrace whatever it is you're going through and then let it go. Try doing a tai chi exercise known as "embracing the tiger," where you take your arms, spread them wide, put your hands together and then draw them—and everything around you—toward your navel, the center of your being. Doing this allows you to take the good with the bad. Then reverse your hands and push them out, releasing your tension. When you can control stress, it can no longer control you. (Follow it with this progressive muscle relaxation technique to reduce stress.)

Once you begin to experience the beneficial aspects of brainwave entrainment, you may be tempted to have these tracks playing all the time during your waking and sleeping hours. This is NOT advisable, nor is it necessary. Remember, brainwave entrainment is exercise for your brain so your brain will need to rest and integrate the new changes that your entrainment regime is creating.
“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.”

♥ I've beeen training in self-hypnosis for a while (under supervision and for a reason) and found that the 8-4 Hz beats put me very quickly in a deeply relaxed state. Definitely the thing! With the timer, I can shut them for the real self-hypnosis. I haven't tried the other beat generators yet, but this one works much better than I expected and clearly does the job. In a few words: I'm impressed!

Theta waves are associated with ➤ Increased sense of inner peace and emotional stability ➤ Deep relaxation ➤ Improved memory ➤ Heightened intuition and inspiration ➤ Calms the chatter of your mind ➤ Increased psychic abilities and sense of spiritual connection ➤ Speed healing, improved physical healing ➤ More restful sleep ➤ Release beneficial hormones related to health and longevity ➤ Reduce mental fatigue ➤ Reduction of anxiety and stress
“A quite different phenomenon results when stereophonic earphones are used and the signals are applied separately to each ear. Under the right circumstances beats can be perceived, but they are of an entirely different character. They are called binaural beats. . . . Binaural beats require the combined action of both ears. They exist as a consequence of the interaction of perceptions within the brain.”
If you’re going to enter a state of meditation, a technique of some sort must be employed that takes you there. (Note – I am fully aware of references to “spontaneous enlightenment experiences”, but these are an entirely different category of phenomena than what is being discussed here and are outside the scope of this discussion. Perhaps another time.)
These tones are similar in that they pulse like binaural beats. The difference is that they don’t need to be listened to using headphones as the pulse, or beat, is not generated by two different frequencies. The sound is an on/off pulse. Although you don’t need headphones to seperate the frequencies listened to, they are recommended. I’ve had just as much response to isochronic tones as I’ve had to binaural beats. I’d try both though, especially if you don’t respond to one or the other.
By simultaneously combining the sounds of two didgeridoos, a desired state of consciousness can be induced in the listener. For example, when one didgeridoo is played in the key of Bb (fundamental frequency of 58 Hz) and a second didgeridoo is played in the key of C (65 Hz), the difference between the frequencies is manifested as a subtle pulsing (in this case 7 Hz). The listener’s dominant brainwave state will sync with this pulsation in a frequency-following response known as brainwave entrainment.
Most wisdom traditions have employed methods that allow the subjects' brain waves to slow down such as meditation, [Hindu] kirtan, [Gregorian, Menzuma or Sufi] chanting, Hebrew davening, Native American drum circles and rain chants, Tibetan prayer bowls, and whirling dervishes and African trance dancing. The rhythm of these wisdom tradition technologies actually slows people's brain waves from their normal busy brain frequency we call Beta (13-30 cycles per second or Hz), to Alpha (8-13Hz) -- meditation, Theta (4-8Hz) -- deep relaxation and dreaming, and Delta (.5-4Hz) -- slow wave or dreamless sleep.
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.
A 2008 study at Hofstra University played two different binaural beats and a control sound (a babbling brook) to patients with high blood pressure. There was no difference between the groups. In one small study from Japan that was published in the Journal of Neurophysiology in 2006, they played various binaural beats to nine subjects, and observed the resulting EEGs. They found great variability in the results. Their conclusion was that listening to binaural beats can produce activity on the human cerebral cortex, however the cause was more likely a conscious auditory reaction and was not correlated to the frequency of the binaural beat. However, a 2005 study published in Clinical Neurophysiology found that they were able to induce a desired frequency in the EEG matching the phantom beat frequency encoded in a binaural beat, however this was with a single subject and was neither blinded nor controlled.
The functional role of neural oscillations is still not fully understood;[6] however they have been shown to correlate with emotional responses, motor control, and a number of cognitive functions including information transfer, perception, and memory.[7][8][9] Specifically, neural oscillations, in particular theta activity, are extensively linked to memory function, and coupling between theta and gamma activity is considered to be vital for memory functions, including episodic memory.[10][11][12]