There are five main categories of brainwave frequencies: Gamma (40Hz+), Beta (13 – 40Hz), Alpha (7 – 13Hz), Theta (4 – 7Hz), and Delta (<4Hz). Each category is associated with a different state of mind; so, for example, when you’re in a peak state of performance, your brain produces Alpha Waves, and when you’re in a deep sleep, your brain produces Delta Waves.
There were no significant differences between the experimental and control conditions in any of the EEG measures. There was an increase of the Profile of Mood States depression subscale in the experimental condition relative to the control condition (p = 0.02). There was also a significant decrease in immediate verbal memory recall (p = 0.03) in the experimental condition compared to control condition.
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.
Eric Bartel is the creator of the Free Binaural Beats website and the sole creator of the audios found here. He specializes in creating binaural beats and isochronic tones along with relaxing ambient meditation music. From his home studio in the Black Hills of South Dakota, Eric is committed to bringing the healing power of binaural beats to anyone who wants to live a more peaceful, relaxed and fulfilled life.

Study after study has shown that brainwave entrainment technology is an effective way to relieve anxiety[4], and that meditation alters brainwave patterns more effectively than regular relaxation [5]. Dr. Jeffrey D. Thompson refers to the “far-reaching possibilities” to be enjoyed by using “this type of vibrational technology” to encourage healing, emotional release, stress reduction, relaxation and, of course, deeper meditation [6].

Uses of audio with embedded binaural beats that are mixed with music or various pink or background sound are diverse. They range from relaxation, meditation, stress reduction, pain management, improved sleep quality, decrease in sleep requirements, super learning, enhanced creativity and intuition, remote viewing, telepathy, and out-of-body experience and lucid dreaming. Audio embedded with binaural beats is often combined with various meditation techniques, as well as positive affirmations and visualization.
The brain will entrain to the strongest stimulus. If you combine binaural beats with isochronic tones, your brainwaves will entrain to the isochronic tones. If anything, when you combine the two I believe it makes the track less effective because it makes it harder for the brain to decipher between the two and synchronise to a single beat. There are lots of websites with compelling marketing about the benefits of combining the two together in some funky way, but I haven’t seen any research or lots of anecdotal feedback even to suggest it’s effective to combine them.
Critics, like Owen Flanagan, PhD, believe that Hanson, and those like him, are overextending the results of current scientific studies.[citation needed] In his book Bodhisattva’s Brain: Buddhism Naturalized, Flanagan presents a more conservative viewpoint of current scientific research and cautions readers against the seemingly exciting results of recent studies.[20] Flanagan does not believe current science supports the idea that positive emotion can be strengthened in the same way that stroke victims can recover use of limbs with use.[20] Flanagan does acknowledge that meditation may be beneficial in some way, but the mechanism of how meditation affects the brain is still clouded.[20] Similarly, Awasthi argues that Meditation is non-specific to the research studies showing clinical efficacy in some cases, though mechanisms remain unclear.[21] Flanagan and Hanson use many of the same scientific studies to attempt to support their differing viewpoint, but both authors identify the need and importance of future studies investigating meditation.
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.

When I first began, I thought I would just do 11 minutes, but I got so into it that I wanted to do it for the full 31 minutes. I experienced that it works in all the ways mentioned above and discovered more every day. I encourage you to practice this meditation and explore what it can do for you. It is good for beginners and seasoned meditators alike. One of the great things about basic Kundalini Yoga meditations is that no previous experience is required. Just tune in with ONG NA MO GURU DEV NA MO and go for it.

The internal rhythm of the brain is called brainwaves and the brainwave pattern varies depending on what a person is doing – sleeping, relaxing, analyzing, etc. Brainwave entrainment is the response of the brain to stimulation with rhythmical sound, such as pulses or beats. After being stimulated with a certain frequency for a period of time, the brain reproduces the same frequency with its internal rhythm, thus achieving a targeted state.
Do note the pre-sets slightly below to the right. Remember: Delta is for deep sleep. Theta is associated with dreaminess. Alpha is a blank or relaxed state of mind and Beta is when you’re active. Try to clear your mind of any thoughts and expectations, and set the volume to an acceptable level. You can play around, but try to give a minute or two for your state of choice. At first glance, you’d think this sounds like an alien spaceship, if not a microwave or a washing machine. Whatever it sounds like to you, if you give it an open mind you will notice there is something weird about this after all. Hopefully, your chosen frequency will have guided you towards the intended effect!
it says the following: “Running a delta sleep session throughout the night is not recommended as it can interrupt the normal sleep cycle”. I’ve been looping pure delta isochronic tones for about 5 days now, and have had quality sleep. Should I continue looping delta or should I let the videos play out without looping them? Will it will harm my health to do loop delta while I sleep?
Beta – Throughout the day our brains are in the beta range with a frequency of about 13hz and up. At this level we are active, busy, and all our emotional responses are at this level. People who are over active, or often depressed, irritable, angry etc., often lose out on the recuperation and recharging that takes place when we are relaxed in the alpha, theta, and delta levels.
Cory Allen [b. 1982] is a composer and mastering engineer living in Austin, Texas. His work focuses on the cultivation of human perception with the intent of altering the listener's state of consciousness. Allen's music is deep, patient, meditative, highly-conceptual and often composed by implementing self-organizing structures, rule-based performances, set pitch classes and a wide variety of instruments.

A popular opinion in the brainwave entrainment community is that listening to isochronic tones without music produces a much stronger effect.  However, in the study by Doherty, Cormac. “A comparison of alpha brainwave entrainment, with and without musical accompaniment” (2014),  it was concluded that brainwave entrainment was equally effective for isochronic tones, both with and without music.
Recordings such as this can include music and sound effects overlaid above special ‘brainwave’ audio that makes meditation more likely. This audio enables brainwave entrainment to take place, where the frequency of sounds and an individual’s brainwaves are encouraged to sync up with each other. For the purposes of meditation, the idea would be to stimulate alpha brainwave activity in the 8-13 Hertz region, a state of relaxed and effortless alertness.This helps achieve deeper results, quicker.

Participants were experienced practitioners of Acem Meditation, a nondirective method developed in Norway. They were asked to rest, eyes closed, for 20 minutes, and to meditate for another 20 minutes, in random order. The abundance and location of slow to fast electrical brain waves (delta, theta, alpha, beta) provide a good indication of brain activity.
This kind of conflicting evidence regarding the effectiveness of binaural beats to produce valid and reliable changes in brain waves abounds in the literature. For example, Rosenfeld, Reinhart, & Srivastava, (1997) found that in a sample of normal college students, alpha and beta audiovisual stimulation showed evidence of brainwave entrainment, but baseline levels of alpha and beta among the participants affected the observed degree of entrainment, producing significant individual differences in response. López-Caballero & Escera (2017) found that administration of binaural beats in the various frequency bands produced no changes in EEG spectral power between the time periods of baseline and those periods with beats presented. Likewise, Wahbeh, Calabrese, Zwickey, & Zajdel (2007) found no effect on brainwaves with the administration of alpha frequency binaural beats. It is easy, however, to find personal testimonials online. 
Regarding split hemisphere isochronic tones. Think of this as two separate isochronic tones tracks playing independently of each other, one playing in one ear and the other one in the opposite ear. Better still, imagine someone playing and recording a drum beat at a rate of 5 taps per second (5Hz – 5 cycles per second). Then a separate recording of a drum beat is made at a rate of 10 taps per second (10 Hz). You then make an audio track where the left ear/channel hears the 5 drum beats recording and the right ear/channel hears the 10 beat recording. With headphones on, each ear can only hear each respective drum beat and not the other. So you are hearing two different beat recordings at the same time, but it’s different in each ear. A split hemisphere isochronic tones track works just the same. You hear two beats at the same time, not two tones as with binaural beats that create a single beat, but two different speeds of beats in each ear. This is what enables you to stimulate and influence each side of the brain with a different frequency of beat. Binaural beats can only stimulate and influence a whole brain effect using a single beat.

Research done under Gerald Oster suggested that binaural beats may be used as a medical tool, especially for diagnosing neurological conditions. In particular, he noticed that untreated sufferers of Parkinson’s disease were unable to “hear” binaual beats but further research indicated successful treatment when the subject was finally able to perceive them at the end of a Parkinson’s treatment regimen. Oster also noted difference in perception in women based on their menstrual cycle, and posited that there may be some connection between the ability to perceive binaural beats and the woman’s levels of estrogen at 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!