However, with this integration will come upheavals as the mind is forced to integrate areas of the brain that were previously sequestered. Repressed memories and unpleasant emotions from the past will often rise to the surface of the mind to be processed and healed. This is sometimes referred to as "processing the shadow" within one's mind and emotions.

Hey, even before we spoke about creating Journey, I was thinking about how people across the world do their spiritual practices and the commonalities between them all. I was thinking, there is the path of stillness—which links right back to what we were talking about getting to a state of deep, profound relaxation and bringing clarity into stillness. Then there’s the path of rhythm, of rocking, of dancing. But there’s always a rhythm to it—even in the movements of Tai Chi, there’s a smoothness, a smooth rhythm. What it never is, is arrhythmic—those are the movements of a more anxious, frightened animal kind of thing. 
Brainwave entrainment is used by millions of adults across the world with no negative effects. However, as with any treatment or therapy, individuals who are prone to seizures should avoid these tones. It is also not advised for pregnant women or very young children whose brain is still developing. If you are concerned about health impacts, discuss it with your health practitioner before you start using our brainwave entrainment products. It is also very important that you use the products in accordance with our instructions.
... [9] While entrainment by binaural auditory beats in the alpha frequency has also been shown to enhance creativity, cognition, memory, and an improvement in intelligence tests and achievement tests in learning disabled boys. [10][11][12][13] The gamma-band activity has been shown to involve in a variety of functions such as attention, memory, and consciousness. Current literature suggests that entrainment by gamma beats promotes cognitive flexibility, modulates visual attention, and enhances creativity. ...

These brainwaves take a lot of energy to produce and you’ll feel really productive and focused when you’re in this state. Your brain in Beta is actively engaged, aware, and reactive. This is a great state for short-term problem solving or being engaged in exciting activities. It’s not a great state for long-term decision making or really thinking through your actions.

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For a few minutes a day, practice being mindful—focusing only on what's going on in the present —whether it's during your workout or taking a break from your work. Try taking a short walk and instead of thinking about what's worrying you, pay attention to your senses—what you see, feel, hear, smell. This can make a huge difference in your emotional and physical well-being when done daily.
To get a full answer you should really get in touch with the owner of the app, because it does really depend on how their track is constructed and how they intend it to work. I have one 50-minute sleep track which takes you down into delta ( and that is designed to just get you to sleep, so you just let play until the end. If you played that track on repeat it might make you jump and wake you up, as the track begins at a higher frequency. I have another 8-hour sleep track which is meant to be played all throughout the night ( So it does depend on the individual track you are using.

Infra-Low brainwaves (also known as Slow Cortical Potentials), are thought to be the basic cortical rythms that underlie our higher brain functions. Very little is known about infra-low brainwaves. Their slow nature make them difficult to detect and accurately measure, so few studies have been done. They appear to take a major role in brain timing and network function. 

Our state of mind, mood, energy level, motivation, and overall well-being all emerge out of the electrical energy produced by our brains. Do you want more control of your moods and thoughts every day? If so, brainwave entrainment is a method which greatly assists many people in finding greater relaxation, better moods, and less anxiety in a way similar to how music uplifts and rejuvenates us, and brainwave entrainment techniques are available embedded into musical arrangements, giving you the benefits of both modalities.
A crossover RCT of a single session of theta stimulation in four healthy adults reported no significant improvement in verbal fluency or attention associated with the intervention and a reduction in immediate recall. Controlled comparisons reported significant benefit from the intervention in all three outcomes measured. Six pre/post studies reported significant benefit from the intervention for 19 of 28 cognitive outcomes.
This music encourages a state of alpha relaxation. The alpha state is a pleasant state of relaxed alertness. It’s a state that many people experience when they are waking up in the morning or when they are just beginning to drift off to sleep at night. While in a state of alpha relaxation, the mind is quite clear and receptive to information, learning is accelerated and one’s sense of creativity is enhanced. The mind is also very open to positive suggestions during this state.
The authors concluded that preliminary evidence suggested that brainwave entrapment was an effective therapeutic tool, but further research was required. The evidence presented appeared to justify the recommendation for further research. In view of the lack of controlled evidence and problems with methodology and reporting in the review, the authors’ conclusions regarding efficacy did not appear reliable.

Another consideration of stress is whether it is acute or chronic. “Acute stress” is what an individual experiences at the time the stressor is encountered (4). The stress response is activated, and the body returns to homeostasis once the challenge of the stressor is removed or the person successfully manages the situation. For example, an individual on the way to an important meeting gets into a traffic jam and realizes she is going to be late; the stress response starts. When she calls her boss and learns that she can conference into the meeting while on the road, the stress response subsides with the resolution of the situation. When an individual experiences acute stress on a consistent basis, such as with overcommitting at work or constant worrying, it is referred to as “acute episodic stress” (4). Individuals who experience acute episodic stress often show signs and symptoms of stress (Table 1) that can negatively impact physical and psychological health. These individuals can learn how to change behaviors and manage their stress to prevent these consequences.

Binaural beats are dual tones, each one slightly different from the other. You hear one tone in each ear and your brain responds by creating a tone to reconcile the difference between the two. Isochronic tones are single tones. The variation in pattern here is brought in by interspersing silence between the sound, which means that your isochronic tone does not have a continuous sound but tones broken up by silences. Studies show that isochronic tones have far more contrast than binaural beats because of the silence and sound pattern. This sharp contrast evokes a faster impact from your brain, prompting it to match the frequency more quickly. Also, isochronic tones are found to be stronger stimulants to the brain.

The pitch frequency measures and describes what a beat sounds like, i.e. does the isochronic beat have a deeper bass sound, or is it high pitched and sharper sounding? The beat waveform frequency describes how many times the beat is repeating per second, i.e. how fast it is beating. You don’t really need to concern yourself about the pitch frequency, as that doesn’t have a direct influence on brainwave entrainment and doesn’t play a part on the measurement on an EEG. I only mentioned it because you were referring to humans not being able to hear below 20Hz. I change the pitch frequency just to suit the mood of the track. For tracks that are to be relaxing, for meditation or sleep, I tend to use a lower pitch frequency so it sounds deeper and more relaxing and I never have that lower than 100Hz. For an energizing, high focus track I might use a more higher pitched 200Hz isochronic tone, because that is sharper sounding and less likely to make you feel sleepy. That’s all you really need to know about the pitch frequency.

Many people experienced in using alpha brainwave entrainment report that the state of mind associated with alpha waves is a time when they feel most consciously connected to their subconscious mind. The intense experience of hypnagogic sleep, reported by some people as a feeling of being awake and asleep at the same time, is also associated with alpha brainwaves.

You may not always be in the mood for meditation when your thoughts are racing, though it is a powerhouse of a stress reliever; you may sometimes face relationship stress that isn't as well-managed by breathing exercises (another highly effective stress reliever) as it might be by learning communication techniques. Guided imagery is fantastic for before bedtime while games are an optimal stress reliever to share with friends.

The composer Alvin Lucier has written many pieces that feature interference beats as their main focus. Italian composer Giacinto Scelsi, whose style is grounded on microtonal oscillations of unisons, extensively explored the textural effects of interference beats, particularly in his late works such as the violin solos Xnoybis (1964) and L'âme ailée / L'âme ouverte (1973), which feature them prominently (note that Scelsi treated and notated each string of the instrument as a separate part, so that his violin solos are effectively quartets of one-strings, where different strings of the violin may be simultaneously playing the same note with microtonal shifts, so that the interference patterns are generated). Composer Phill Niblock's music is entirely based on beating caused by microtonal differences.
Exercise and stress research has typically focused on aerobic exercise. There have been consistent findings that people report feeling calmer after a 20- to 30-minute bout of aerobic exercise, and the calming effect can last for several hours after exercise. Recently, there has been an increased amount of research on the role of mind-body types of exercise such as yoga or Tai Chi. Unfortunately, there is somewhat limited research on the role of resistance exercise in stress management.
The Frequency following response (FFR), also referred to as Frequency Following Potential (FFP), is a specific response to hearing sound and music, by which neural oscillations adjust their frequency to match the rhythm of auditory stimuli. The use of sound with intent to influence cortical brainwave frequency is called auditory driving,[39][40] by which frequency of neural oscillation is 'driven' to entrain with that of the rhythm of a sound source.[41][42]