When delta waves are present, our awareness of the external world decreases and shuts off. People with ADD have problems with delta waves occurring when they are trying to focus, and focus and attention become increasingly impossible with stronger delta waves. Studies show a reduction of anxiety, improvements in insomnia, and elimination of headaches when people engage in sessions of delta brainwave entrainment.
... These factors may be the specific frequency of BB; the targeted population-because it is known that older people have different quality of brainwave activity than, e.g., youngsters (Bazanova & Aftanas, 2008;Clark et al., 2004), and the tests used to detect the possible changes in working memory capacity. Based on the research showing a positive impact of alpha-range BB on cognitive functioning, specifically attention, auditory sequential memory, working memory, working memory storage, reasoning ability, cognitive processing and hemispheric synchronization, (Carter & Russell, 1993;Cruceanu & Rotarescu, 2013;Foster, 1990;Kennerly, 1994;McMurray, 2006) as well as on the wealth of research documenting the important role of alpha brain wave activity on vigilance, in-hibitory processes, attention, filtering out irrelevant information working memory, the visuo-spatial component of working memory, perceptual abilities and information processing speed (Braboszcz & Delorme, 2011;Clark et al., 2004;Engle et al., 1999a;Freunberger et al., 2011;Klimesch et al., 2007;Lachat et al., 2012;Oprisan, 2004;Palva & Palva, 2007;Rihs et al., 2007;Sauseng et al., 2009;Tuladhar et al., 2007;VanRullen & Koch, 2003), we believe that BB of a frequency that corresponds to the alpha range of brain activity has a temporary effect on working memory capacity. In our study, subjects were exposed to 9.55 Hz BB stimulation while we measured their working memory capacity through the Automated Operation Span Task (AOSPAN). ...
No. The frequencies are consistent throughout the duration of each music production we offer. It could be argued that a better approach is to change the frequency over time, starting at a higher frequency when the listener is alert and slowly ramping down as the music progresses and the listener becomes more relaxed. So why have we not taken this approach?

Binaural beats, or binaural tones, are auditory processing artifacts (apparent sounds) resulting from the stimulation of the ears with two different sound frequencies. In fact, when two different vibrations are delivered to the brain separately through each ear, using stereo headphones, the two hemispheres of the brain function together to “hear” and perceive not the external sound signals, but a third phantom signal. This resulting signal, discovered in 1839 by Heinrich Wilhelm Dove, is called “binaural beat”. The effect on the brain waves depends on the difference of each tone. For example, if a sound frequency of 300 Hz is played in the left ear and 307 Hz in the right one, then the binaural beat would have a frequency of 7 Hz (“frequency following response”) which corresponds to the Alpha brain state, generally associated with relaxation, visualization and creativity. The beating tone is perceived as if the two tones mixed naturally, out of the brain. For the binaural beat effect to occur, the difference between the two frequencies must be small (less than or equal to 30 Hz), otherwise, the two tones will be heard separately, and no beat will be perceived.
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. 

Beta brainwaves are further divided into three bands; Lo-Beta (Beta1, 12-15Hz) can be thought of as a 'fast idle', or musing. Beta (Beta2, 15-22Hz) is high engagement or actively figuring something out. Hi-Beta (Beta3, 22-38Hz) is highly complex thought, integrating new experiences, high anxiety, or excitement. Continual high frequency processing is not a very efficient way to run the brain, as it takes a tremendous amount of energy. 

I have read something different about theta waves and learning languages. A University of Washington study tested students resting brainwave activity before learning French. They found that students with a higher amount beta/gamma and a lower amount of delta/theta activity were better at acquiring a second language. When you are dominant in theta, that is the lowest and most deeply relaxed awakened state you can be in. I think it would be much harder to really concentrate, fully understand and learn new information while in a theta state, so I would personally consider using theta while studying.
For example, if a 530 Hz pure tone is presented to a subject's right ear, while a 520 Hz pure tone is presented to the subject's left ear, the listener will perceive the auditory illusion of a third tone, in addition to the two pure-tones presented to each ear. The third sound is called a binaural beat, and in this example would have a perceived pitch correlating to a frequency of 10 Hz, that being the difference between the 530 Hz and 520 Hz pure tones presented to each ear.
Binaural beats were discovered in 1839 by a German experimenter, H. W. Dove. The human ability to "hear" binaural beats appears to be the result of evolutionary adaptation. Many evolved species can detect binaural beats because of their brain structure. The frequencies at which binaural beats can be detected change depending upon the size of the species' cranium. In the human, binaural beats can be detected when carrier waves are below approximately 1000 Hz (Oster, 1973). Below 1000 Hz the wave length of the signal is longer than the diameter of the human skull. Thus, signals below 1000 Hz curve around the skull by diffraction. The same effect can be observed with radio wave propagation. Lower-frequency (longer wave length) radio waves (such as AM radio) travel around the earth over and in between mountains and structures. Higher-frequency (shorter wave length) radio waves (such as FM radio, TV, and microwaves) travel in a straight line and can't curve around the earth. Mountains and structures block these high-frequency signals. Because frequencies below 1000 Hz curve around the skull, incoming signals below 1000 Hz are heard by both ears. But due to the distance between the ears, the brain "hears" the inputs from the ears as out of phase with each other. As the sound wave passes around the skull, each ear gets a different portion of the wave. It is this waveform phase difference that allows for accurate location of sounds below 1000 Hz(9). Audio direction finding at higher frequencies is less accurate than it is for frequencies below 1000 Hz. At 8000 Hz the pinna (external ear) becomes effective as an aid to localization. In summary it's the ability of the brain to detect a waveform phase difference is what enables it to perceive binaural beats.
However, very experienced practitioners of meditation are able to enter a Delta state and maintain consciousness at the same time. Yoga nidra or “yogi sleep” is a sleep-like state which yogis report during their meditations. This lucid sleeping state is among the deepest possible states of relaxation while still maintaining full consciousness (“super-conscious mind”). In this state, experienced yogis are able to regulate their body temperature and heart rate.
Point #3 can easily be the case if you are still subscribing to the false idea that just listening to an entrainment track is meditation all by itself. Some unscrupulous marketing copy of various entrainment products uses phrases such as; “Our meditation CD meditates you…” which is of course, complete nonsense. I was asked recently to review one marketing ad which claimed, “With our meditation CDs you don’t need to know how to meditate…” This is worse than nonsense, it’s hogwash. That’s like saying, “If you use our wonderful plates and silverware you don’t even need to know how to cook.” If you believe that you’re unlikely to get many takers on your dinner invitations.

I have a strange reaction to Binaural beats, as well as isochronic beats, and anything similar. After listening, I often feel vey fatigued, nauseous, and sometimes quite depressed. This effect can last a few days. So I stay away from it now, as well as guided meditations that have such beats in the background. Have you heard of this kind of reaction before?

Nothing is more stressful than being unprepared. Get organized so you're ready for the next day, taking a few minutes to make a to-do list and clean up before you leave. Knowing you've got everything covered means you'll be less likely to fret about work in the evenings. When you come in the next morning, you'll have the sense that you're in control of the situation and can handle it. This sets a positive tone for the day, which can help you get more accomplished. (You can even turn your nightly beauty routine into a stress-relieving practice.)

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.

Isochronic tones are basically just a single tone with the volume being turned on and off at regular intervals. When you apply the same effects to music or a noise, it’s usually referred to as amplitude entrainment effects (in Mind Workstation anyway). When you apply the on/off effect to music or noise it’s usually done by targeting a specific frequency range in the sound and only turning that part on/off, leaving the rest of the music/noise untouched. What that does is allow parts of the music/noise to play without being distorted/interrupted, making it sound more pleasant to listen to. It produces a kind of fluttering sound as I like to call it and you can adjust the level of intensity.
For example, if a 530 Hz pure tone is presented to a subject's right ear, while a 520 Hz pure tone is presented to the subject's left ear, the listener will perceive the auditory illusion of a third tone, in addition to the two pure-tones presented to each ear. The third sound is called a binaural beat, and in this example would have a perceived pitch correlating to a frequency of 10 Hz, that being the difference between the 530 Hz and 520 Hz pure tones presented to each ear.
There’s a growing body of research suggesting that binaural beats can reduce different forms of anxiety, from mild to chronic. One especially interesting study looked at the effects of binaural beats on anxiety among patients preparing to undergo surgery—a life circumstance that is pretty anxiety provoking for most anyone. Over a period of six months, patients spent 30 minutes on the day of their surgery listening to binaural beats. Compared to patients who listened to a soundtrack that did not include binaural beats—and patients who received no “beats” therapy at all—the binaural beat listeners experienced significantly greater reductions in their anxiety levels.
Aletheia Luna is an influential psychospiritual writer whose work has changed the lives of thousands of people worldwide. After escaping the religious sect she was raised in, Luna experienced a profound existential crisis that led to her spiritual awakening. As a spiritual counselor, diviner, and author, Luna's mission is to help others become conscious of their entrapment and find joy, empowerment, and liberation in any circumstance. [Read More]
Beating can also be heard between notes that are near to, but not exactly, a harmonic interval, due to some harmonic of the first note beating with a harmonic of the second note. For example, in the case of perfect fifth, the third harmonic (i.e. second overtone) of the bass note beats with the second harmonic (first overtone) of the other note. As well as with out-of tune notes, this can also happen with some correctly tuned equal temperament intervals, because of the differences between them and the corresponding just intonation intervals: see Harmonic series (music)#Harmonics and tuning.
Entrainment guides our brainwaves into targeted ranges, but they are ranges we go through naturally many times every day. LifeFlow 10, for example, takes the brain to a 10Hz frequency. We experience this same frequency when closing our eyes and taking a deep breath, or when consciously relaxing physical tension in the body, or when we find ourselves lost in a daydream, or when we view a beautiful sunset, or when we find ourselves caught up in an especially peaceful bit of music. If there was a cause-and-effect relationship between these 10Hz brainwaves and our face flushing, then our face should also flush when we enter that daydream, listen to that piece of music, watch that sunset, or close our eyes and relax. The same brainwave patterns are present during all those activities as they are while listening to LF-10. But these other activities don’t bring on the same face flushing.

With its focus on full, cleansing breaths, deep breathing is a simple yet powerful relaxation technique. It’s easy to learn, can be practiced almost anywhere, and provides a quick way to get your stress levels in check. Deep breathing is the cornerstone of many other relaxation practices, too, and can be combined with other relaxing elements such as aromatherapy and music. While apps and audio downloads can guide you through the process, all you really need is a few minutes and a place to stretch out.

Theta is very subtle. It is one of the most elusive and extraordinary brain states you can explore. Theta is a state of somnolence with reduced consciousness; you are neither fully awake nor asleep yet. It is also known as the “Twilight state” or “Stage 1 Sleep” which you normally only experience fleetingly as you wake or drift off to sleep. In the Theta brain state, your senses are withdrawn from the external world and focused on signals originating from within.
Binaural beats are pretty simple. Basically, you take two frequencies that are similar and play each one through it’s own stereo headphone. The two competing frequencies will work together in your mind to produce a pulsing. That pulse will be a certain frequency that corresponds to a number in hertz that is linked to what your brain produces when you are in certain states of consciousness.

To use your senses to quickly relieve stress, you first need to identify the sensory experiences that work best for you. This can require some experimentation. As you employ different senses, note how quickly your stress levels drop. And be as precise as possible. What is the specific kind of sound or type of movement that affects you the most? For example, if you’re a music lover, listen to many different artists and types of music until you find the song that instantly lifts and relaxes you.

Participants in the included studies were children and adults, either healthy or with conditions such as learning disabilities, attention deficit hyperactivity disorder, migraine, stress, anxiety and myofascial pain. Interventions included single, alternating, ascending or descending frequencies of photic or auditory stimulation or audiovisual entrainment selected either by the participant or by the investigator. Nearly half the studies used single sessions and the rest used multiple sessions ranging from nine to 100. Length of session varied from 0.5 seconds to 60 minutes. Frequency of session varied from twice daily to weekly. Outcomes reported in the review included cognition (including verbal skills, performance skills, attention, memory and overall intelligence/achievement), short- and long-term stress, pain, headache/migraine, mood, behavioural problems and premenstrual syndrome (PMS).