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).
Theta waves also have been observed in moments when a person recalls information from the past, and this may be what links them also to improvement in learning ability. We also experience theta waves when we go into automatic pilot mode, such as when doing a repetitive task like driving a familiar route where the mind become disconnected while you still drive safely toward your destination.
There's no doubt that brainwave entrainment audio is a great technology for anyone who is interested in encouraging altered states of consciousness and it certainly can help people to reach deeper states of relaxation than they might normally have access to. I myself will often listen to brainwave entrainment music in order to enhance my practice of meditation. But let’s keep a balanced perspective, put all the marketing hype to one side for a moment and acknowledge that there is no brainwave entrainment technology in this world that can make you meditate like a Zen monk “at the touch of a button”, despite what some might like you to believe. The mind is NOT a machine. It moves through various states of consciousness in an organic way and at a natural pace. We certainly can guide and accelerate that process with the use of brainwave entrainment audio, but we cannot control it with the same sort of specificity and immediacy as you might control the speed of the car you drive.

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.
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.
None of our formulas contain gluten. The pure Italian wheat-based grain alcohol we use leaves all gluten behind when distilled, and comes with a gluten-free test certificate. The only other grain used in any of the formulas is Milky Oats, which is sustainably harvested and sorted in a botanical house. It is not processed with, or contaminated by, other grains.
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.
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.

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.
Theta brain waves occur most often in sleep but are also dominant in deep meditation. Theta is known to be a dreamlike state with vivid imagery, intuition and information beyond your normal conscious awareness. This state of mind is excellent for psychic experiences to occur, as well as astral projection and extended remote viewing. To reach this state without falling asleep while meditating takes practice.

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.

Wouldn’t it be a blessing if you could find a way to move through each day with a greater sense of peace and harmony, with heightened creativity and intuition, with a sharper intellect and a more positive outlook? For many people today, the deep, effortless meditation that brainwave entrainment provides is the key to a more fulfilling, peaceful and successful life.

Consider the following analogy. Imagine a ballroom full of people dancing together. When the music changes to a faster tempo, the dancers move faster in response to this. When a slower piece of music is played, the dancers’ rhythm slows down as well. In a similar way, the frequency of your brain will change in response to the frequency of the binaural beat that it is exposed to. For example, a person who is in a state of very deep meditation may have a dominant brainwave frequency of 5 hertz, so by listening to a binaural beat with a frequency of 5 hertz you can entrain your own brainwaves to a similar state.
Start by kneading the muscles at the back of your neck and shoulders. Make a loose fist and drum swiftly up and down the sides and back of your neck. Next, use your thumbs to work tiny circles around the base of your skull. Slowly massage the rest of your scalp with your fingertips. Then tap your fingers against your scalp, moving from the front to the back and then over the sides.

With brain wave entrainment technology, changing brain wave states is an instantaneous and effortless process. The 'periodic stimulus' can be sound, vibrations and/or light. We have found that we get the best results with blinking lights which are experienced through closed eyelids. This is only problematic for people with existing diagnosis of photo-induced epilepsy, as blinking lights can induce a seizure in them. The programs are enhanced with Deepak Chopra doing the narration along with holographic sound effects and original music composed and performed by Rudy Tanzi.
Whenever we become very relaxed and the usual chatter of the mind slows down a little bit, if we remain aware and do not slip into sleep or unconsciousness, we begin to perceive things that we had not noticed before. This is slightly different than the issue of “expectations” discussed previously, although a relationship to them can develop which will be discussed below. These have to do with the fact that in our typical state of consciousness our mind is racing so fast and so loud, and our body is so engaged with activity and physical tension, that we are unaware of some subtle perceptions that are there all the while, but which get buried beneath all the physical and mental noise.
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.
Gaia Meditation Gamma programs are specifically designed to: stimulate cognitive functions, help for higher learning and greater focus, improve IQ, expand consciousness and inspiration. The Dalai Lama meditates 4 hours every morning, which must stimulate his Gamma activity in a tremendous way. However, even if you have never practiced meditation, our Gamma waves programs will take you easily and rapidly to the Gamma brain state.
I wouldn’t personally recommend listening to delta wave frequencies for depression, so I’m not sure who advised you to do that? People with depression usually have a higher ratio of theta and delta wave activity, so I would normally recommend listening to high alpha wave and low beta wave frequencies, to help balance things. I have some 10Hz alpha tracks for serotonin release, which you can try for free on my YouTube channel here: I also recommend you give these SMR (low beta wave) tracks a try: I hope that helps.
Alpha (12hz – 8hz) – Awake, but deeply relaxed. Simply closing your eyes will produce alpha brainwaves. This category is associated with daydreaming, visualization, imagination, light meditation. Brainwave expert Anna Wise called the alpha range the bridge between beta and theta. (More information can be found in Wise’ book The High-Performance Mind)
While the physiological and psychological processes being uncovered by brain science in the study of brainwaves is sometimes complex and still being investigated, certain basic principles are well-established, easily understood, and helpful for achieving the most effectively use of brainwave entrainment when seeking relaxation, improved sleep, lowering of anxiety, or other goals. This important background information and scientific knowledge presented here includes: 
These brainwaves are actually a bit of a mystery. They’re the highest frequency you can achieve, but scientists are a little dumbfounded by them. Unlike the next set of brainwaves (Alpha and Beta), Gamma brainwaves don’t’ really translate to feeling active and alert. Rather, what’s been discovered is that in Gamma, neurons are firing so harmoniously, that people often feel like they are having a spiritual experience. This brainwave state has been associated with expanding consciousness and understanding the value of universal love and harmony.
It is important to note that not all stress is bad. Everyone experiences a certain amount of stress on an almost daily basis, and it cannot be completely eliminated. Stress becomes a problem when too much is experienced, and it has a negative impact on behaviors, relationships, and health. The term “eustress” refers to positive stress that is associated with improved performance and productivity. “Distress” is negative stress that is associated with performance decrement and negative health consequences. The individual’s perception of the stressor and coping resources determine whether a situation is eustress or distress. College graduation is a stressor for most. The student who has a job or who has been accepted to a graduate program likely perceives the stress of graduation as eustress, whereas the student who has student loans and no immediate plans of a job or further education perceives distress.

Everyone knows stress can cause you to lose sleep. Unfortunately, lack of sleep is also a key cause of stress. This vicious cycle causes the brain and body to get out of whack and only gets worse with time. Make sure to get the doctor-recommended seven to eight hours of sleep. Turn the TV off earlier, dim the lights, and give yourself time to relax before going to bed. It may be the most effective stress buster on our list.
In 1956, the famous neuroscientist W. Gray Walter published the results of studying thousands of test subjects using photic stimulation, showing their change in mental and emotional states. He also learned that photic stimulation not only altered brainwaves, but that these changes were occurring in areas of the brain outside of vision. In Walter’s words:
Gamma brainwaves occur during creative thinking and processing of memory and language and in many learning activities. These brainwaves are not present at all when a person is under anesthesia, but return as soon as the person becomes conscious again. Multiple scientific studies have shown gamma brainwave entrainment to be helpful for reducing distractibility, improving short-term memory, improving motor coordination, and relieving migraine headaches.
LEARNING OBJECTIVE • Exercise can be an effective component of a stress management program, and all types of exercise can be beneficial for stress management. Exercise programs consistent with the current recommendations to improve health can be prescribed to manage stress. Fitness professionals should recognize that it might be necessary to refer a client to a psychologist or other health care provider to help develop strategies for managing stressors that produce chronic and acute episodic stress.
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.
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.