, that is, the average of the two frequencies. It can be noted that every second burst in the modulation pattern is inverted. Each peak is replaced by a trough and vice versa. However, because the human ear is not sensitive to the phase of a sound, only its amplitude or intensity, only the magnitude of the envelope is heard. Therefore, subjectively, the frequency of the envelope seems to have twice the frequency of the modulating cosine, which means the audible beat frequency is:[5]

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.

Transparent Corp's Research Area is arguably the most comprehensive resource for collated brainwave entrainment research.   Update: the main research area on Transparent Corp's website is currently being updated, so it is offline.  However, you can still access their peer-reviewed research paper as a PDF here: “A Comprehensive Review of the Psychological Effects of Brainwave Entrainment“.
Results of this research proved that, indeed, the brain would entrain itself to the frequency equal to the difference between the two frequencies played. So if a subject listened to a 210 hertz tone in one ear and a 214 hertz tone in the other, the 4 hertz difference is the perceived “beat” that the brain, after listening for a while, will match itself to.
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. 
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.
In the last two posts, I discussed some unusual ways in which some people respond to certain very ordinary sounds. In the case of ASMR, sounds like tapping, tearing, and popping can lead to tingling sensations associated with relaxation and even drowsiness. In the case of misophonia similar sounds, like swallowing and lip-smacking, can also cause a tingling sensation, but one accompanied by disgust and even rage. Binaural beats are a different kind of sound and many people report finding certain of them relaxing and even conducive to falling asleep.  Other people do not like them and after hearing them once never want to hear them again. 
There is a solution, which, although you may not have heard about it, has been around (and scientifically tested!) for decades now. By using binaural beats, you can ease your brain from its active state into a more restful state simply by listening to a different frequency wavelengths of sound in each ear. Because two different wavelengths are entering through two different entrances (your ears), that difference is perceived as a “beat” (though it may sound like a warble to some) that resonates at the frequency equal to the difference. The brain will entrain (match) itself to the beat produced by the difference in wavelengths. If the difference between the two wavelengths is less than seven hertz, your brain will fall into a state of deep relaxation, also known at the theta range.
Theta also plays an important part in behavior modification programs and has been used in the treatment of drug and alcohol addiction. Because theta brainwave activity induces an "endorphin high" it can reduce the desire for mind altering substances. Also, because theta is associated with heightened receptivity, it is the ideal state to reprogram your mind with positive thoughts that assist in changing habits and behaviors.
After buying a new bed and feeling restless in a new home, I decided to buy a few meditation tracks. I have to say, for the last 2 months, I play this mp3 every night and fall asleep within 5-10 minutes when earlier it took me much longer. I am more relaxed when I sleep! Only hiccup is sometimes I wake up in the night, however, I fall back asleep quickly since the music is on repeat mode. A great purchase and highly recommended for people with insomnia!
Isochronic tones work just the same in delta as they do in alpha, theta and beta and they are widely used in the brainwave entrainment community to help people sleep. Like you, I’ve also seen some websites saying they don’t work in delta, but it’s a bit like the game of Chinese Whispers, where someone makes a comment and then after it gets passed around and shared a lot the message gets distorted and appears to be a fact. I don’t know of any scientific reason why they wouldn’t work in delta. I remember some people talking about this on a brainwave entrainment forum many years ago. They were saying they found isochronic tones a bit too abrupt for using to help them sleep and they preferred binaural beats, as they thought they were a more soothing sound. That was just a personal preference shared by a couple of prominent forum members at the time and some people then took that as a fact for everyone. That’s where I think that belief originated from.
Our brains follow cues from outside stimuli, and brainwaves mimic the pulse rates of the sounds we expose it to. So, by creating tracks that pulse sound waves at a desired frequency, we can effectively coax our brain into that state. In layman's terms; by listening to some strange sounding brainwave frequency audios, we can literally slip our brain into a state of feeling calm, alert, focused, energized... and the list goes on. Pretty cool, right!?
Brainwave entrainment also happens with the use of pulsating light, and visual and auditory stimuli are sometimes combined for additional effect and visual stimuli is used alone. Using brainwave entrainment techniques is safe for almost everyone, the exception being pregnant women and people who have seizure disorders who should check with their physician before using these methods.
Hi Sahil, it’s hard for me to speak about other people’s tracks and videos, as I don’t know how they created them either. If you’re interested in a particular track/video and unsure about it, try asking the creator a question or two about the track, what frequencies were used and for how long, what software they used etc. Then make your own judgement based on how they reply to you. Jason
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.
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.)
Using a unique approach that combines the best methods from many different fields, the Neuro-Programmer 2 is an effort-free software application with unlimited potential and broad capabilities. Although it is incredibly simple to use, it remains the most effective self-help tool on the market today. Using NP2 is the single best way to achieve rapid and long lasting personal change.
Your brainwave activity during sleep is largely distinct from your brain activity when you’re awake. (REM sleep is one exception to this—during REM, your brain is active in ways very much like when you’re awake.) During non-REM sleep, the slower, lower frequency theta and delta waves dominate, compared to the alpha and beta waves that are prominent when you’re alert and active.
I forgot to tell you, after using your meditation for a few weeks, I woke up one morning with the most vivid recollection of having an out of body experience […shortened…] I am hoping to experience this again and control myself the next time. Thank you for enabling me to remember this extraordinary experience. I never believed they were real until I used your program.
Resonant entrainment of oscillating systems is a well-understood principle within the physical sciences. If a tuning fork designed to produce a frequency of 440 Hz is struck (causing it to oscillate) and then brought into the vicinity of another 440 Hz tuning fork, the second tuning fork will begin to oscillate. The first tuning fork is said to have entrained the second or caused it to resonate. The physics of entrainment apply to bio-systems as well. Of interest here are the electromagnetic brain waves. The electrochemical activity of the brain results in the production of electromagnetic wave forms which can be objectively measured with sensitive equipment. Brain waves change frequencies based on neural activity within the brain. Because neural activity is electrochemical, brain function can be modified through the introduction of specific chemicals (drugs), by altering the brain's electromagnetic environment through induction, or through resonant entrainment techniques.
Many studies on mindfulness meditation, assessed in a review by Cahn and Polich in 2006, have linked lower frequency alpha waves, as well as theta waves, to meditation.[4] Much older studies report more specific findings, such as decreased alpha blocking and increased frontal lobe specific theta activity.[5] Alpha blocking is a phenomenon where the active brain, normally presenting beta wave activity, cannot as easily switch to alpha wave activity often involved in memory recall. These findings would suggest that in a meditative state a person is more relaxed but maintains a sharp awareness. Two large, recent comprehensive review works, however, point to poor control and statistical analyses in these early studies and comment that it can only be said with confidence that increased alpha and theta wave activity exists.[4][6]
As we start to fall asleep, we naturally pass through the relaxed, drowsy alpha state, dropping into the sleep states of theta and delta. Dreaming occurs in the theta state, but most of the time when we’re asleep in the theta state, we are unconscious, and unable to consciously control the dreams we experience. When we begin to wake up, our dominant brainwaves pass into the lower alpha wavelengths, but usually as this happens, we wake up out of our dreams. The key to lucid dreaming is to approach the alpha wavelength, but, before you fully wake up, move back down into the dreaming theta state. This way, your subconscious begins to wake up enough for you to take control of your surroundings, but you’re still asleep enough that those surroundings are a wonderfully malleable dream instead of reality.
I tried other companies the last few years or so….among the likes that mainly used binaural audio and the deepest I was really ever to achieve was alpha state….maybe theta once or twice over the last few years. It takes incredible dedication and practice to achieve the deep, renewing states of meditation that are most sought after…..I listened to the theta meditation mp3 last night and within what seemed like a few minutes my mind was flooded with imagery…memories long gone…my body was sleeping, heavy as lead, but my mind was crystal clear, aware of my surroundings. I could barely even open my eyes!
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.

Binaural beats work by playing a different tone in each ear, and in the process the brain creates a “phantom tone” which is the difference between the two tones (for example if you play a 300 hz tone in one ear and a 310 hz in the other ear the brain will produce a 10 Hz phantom tone.) If this phantom tone is 10 hz the brain will gradually be led to a dominant brainwave frequency of 10 hz (this has been measured by EEG devices). If the tone is 7 hz the brain will gradually be led to a 7 hz dominant frequency, and so on.

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.

According to the Wikipedia entry “(i)n acoustics a beat is an interference pattern between two sounds of slightly different frequencies, perceived as a periodic variation in volume whose rate is the difference of the two frequencies.” Further, a binaural beat is “… an auditory illusion perceived when two different pure-tone sine waves, both with frequencies lower than 1500 Hz, with less than a 40 Hz difference between them, are presented to a listener dichotically (one through each ear)”. If the two frequencies are, say, 5 Hz apart as in 500 and 505 Hz, then a third tone at 5 Hz will be heard in addition to the two pure tones. What this technique allows for is the creation of an apparent auditory signal that can be perceived and that is at a predictable frequency. In this way, relatively low frequencies can be generated that can be easily perceived and that can correspond to the common brainwave frequency bands. These are often categorized as delta (0.5 – 4 Hz), theta (4 – 7 Hz), alpha (8 – 12 Hz), and beta (13 – 16 Hz). You may find somewhat different ranges and bands other than these listed depending on the source you consult. It is also possible to produce flashes of light that can be administered within these frequency bands but there is some risk of inducing seizures in susceptible individuals. While the most common frequency range for inducing seizures is 15 – 25 Hz, unfortunately, the possible range is 1 – 65 Hz, which covers essentially the whole range of standard EEG frequency bands. This makes use of sound stimulation safer than visual or combined audio/visual stimulation. 

Entrainment is a phenomenon seen is a wide variety of different natural circumstance. In the field of chronobiology, the study of biological rhythms in living organisms, entrainment is the synchronization of a circadian rhythm with the rhythm of an external pattern, such as the synchronizing of women’s menstrual cycles with the phases of the moon or with one another in a group.
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.
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. 
Electroencephalography (EEG) has been used in many studies as a primary method for evaluating the meditating brain. Electroencephalography uses electrical leads placed all over the scalp to measure the collective electrical activity of the cerebral cortex. Specifically, EEG measures the electric fields of large groups of neurons. EEG has the benefit of excellent temporal resolution and is able to measure aggregate activity of portions or the entire cortex down to the millisecond scale. Unlike other imaging based methods, EEG does not have good spatial resolution and is more appropriately used to evaluate the running spontaneous activity of the cortex. This spontaneous activity is classified into four main classifications based on the frequency of the activity, ranging from low frequency delta waves (< 4 Hz) commonly found during sleep to beta waves (13–30 Hz) associated with an awake and alert brain. In between these two extremes are theta waves (4–8 Hz) and alpha waves (8–12 Hz).

... Several studies have looked at the possible effects of binaural beats within the alpha range on cognitive abilities. A significant improvement in cognitive processing, as measured by the Stroop Effect exercise, was found by a BB stimulation of 10.2 Hz frequency (Cruceanu & Rotarescu, 2013).Carter and Russell (1993)exposed 8 to 12 year old boys with learning disabilities to 8-week long 10 and 18 Hz BB stimulation sessions, and they found an improvement in Raven's progressive matrices and in a subtest of auditory sequential memory (Carter & Russell, 1993).McMurray (2006)assessed the effect of 7 and 11 Hz BB on alpha brainwave activity, working memory, and attention in healthy elderly people, who are known for experiencing gradual decrease in physiological alpha activity. The 2 minutes exposure to BB resulted in an altered electrical activity in the brain. ...

Delta brainwaves are slow, loud brainwaves (low frequency and deeply penetrating, like a drum beat). They are generated in deepest meditation and dreamless sleep. Delta waves suspend external awareness and are the source of empathy. Healing and regeneration are stimulated in this state, and that is why deep restorative sleep is so essential to the healing process.

E I slept n cy time u attempted it I had the worst feeling ever my brain was so so heavy had a serious gravitational pulling to the ground and terrible twisting and painful movements in my head they b come u bearable I do t know what’s wrong my body seems to want to stay in a weird relcexd kind of state where I just want to stay in that state all the time I feel like a paralysis my whole body is weighted numb and dead I stopped all meds but it still happening nobody knows anything about this music nobody believe it’s cause ld me problems I am really u happy my life is a mess my head feels so so heavy and weighted I can’t hold it up I had a neck injury a while before I had listened to the music I been every where I seen all doctors had mri nobody can help me I do t know wats caused this my body and head does not want to co e out this state I can’t live this way please can u help me is the bi aural beats to blame I just do t know it seems
The huge problem will all such studies is that there is a clear placebo effect on any kind of mental performance whenever the subject is observed. Do any intervention, then measure performance, and the intervention and measurement are likely to cause an increase in effort and attention which will increase performance. This generic “placebo” effect needs to be factored out of any such study by proper blinding and controls in order for the results to have any meaning at all.
Hi EJ, at the moment, there hasn’t been any research to give an indication of how long you should or shouldn’t listen for. Over time, I’ve seen people use my tracks for longer and longer. I started off providing 30-minute study tracks, but through demand, I extended them to 3-hours. I know from the many thousands of comments I’ve had on YouTube that a large number of people play those 3-hour tracks on repeat, or listen to different ones, one after the other throughout the day. I’ve also seen apps where you can play tracks like mine on continuous repeat. So it’s common for people to listen to them all day while they are studying.

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. 

Binaural beats can easily be heard at the low frequencies (< 30 Hz) that are characteristic of the EEG spectrum (Oster, 1973). This perceptual phenomenon of binaural beating and the objective measurement of the frequency-following response (Hink, Kodera, Yamada, Kaga, & Suzuki, 1980) suggest conditions which facilitate entrainment of brain waves and altered states of consciousness. There have been numerous anecdotal reports and a growing number of research efforts reporting changes in consciousness associated with binaural-beats. "The subjective effect of listening to binaural beats may be relaxing or stimulating, depending on the frequency of the binaural-beat stimulation" (Owens & Atwater, 1995). Binaural beats in the delta (1 to 4 Hz) and theta (4 to 8 Hz) ranges have been associated with reports of relaxed, meditative, and creative states (Hiew, 1995), and used as an aid to falling asleep. Binaural beats in the alpha frequencies (8 to 12 Hz) have increased alpha brain waves (Foster, 1990) and binaural beats in the beta frequencies (typically 16 to 24 Hz) have been associated with reports of increased concentration or alertness (Monroe, 1985) and improved memory (Kennerly, 1994).
At any rate, I am enjoying the product immensely. I’m keeping a journal in which I’m recording my thoughts & observations as well as memory and cognition scores just as a sort of completely unscientific pet project, out of curiosity. So far, I’ve benefited from being better rested and more focused as a result of your product and that alone is worth the price of admission but I hope to be able to show that over an extended period of time, EquiSync can also improve working memory, cognition, &etc. I’ll be sure to share the data I collect with you if I get anything of statistical significance.
That all said, we are all different and have our own different limits. So I generally advise that you just be aware of how you are feeling, and if you feel like you are getting a bit fatigued from it, it’s probably time to stop or at least take a break. When listening over long extended periods, I recommend that you keep yourself well-hydrated. Your brain needs a good supply of water to function well, especially if you are studying hard and increasing your brainwave electrical activity.
Brainwave Entrainment has been used possibly as far back as 200AD, where Ptolemy of the Ancient Greeks noted the effect of flicking sunlight created by a spinning wheel. The first recorded clinical application was by a French psychologist, who again used a spinning wheel but this time illuminated with a lantern instead of the sun. He noted that his patients appeared calmer when they looked into the flickering light, so he used it as a relaxation technique whenever it was needed.
Like many complementary therapies, the issue most people have about meditation is in its execution. Thanks to the rapid rise of technology in our lives, we seem to be busier than ever. Our minds are occupied during most of the time we are awake, and we only really shut off when we finally go to sleep at night, which means that finding the opportunity to meditate daily can be difficult.
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.
In shamanic traditions, drums have long been used to transport the shaman out of his or her body into other realms of reality through the use of constant rhythmic vibrations. Researcher Melinda Maxfield, studying the Shamanic State of Consciousness, found that the steady rhythmic beat of the drum struck 4.5 times per second was the key to transporting a shaman into the deepest part of his shamanic state of consciousness. With the invention of the EEG (electroencephalograph) Biofeedback researchers discovered that theta brain waves oscillate at 4.5 beats, or cycles, per second. In direct correlation, we see similar effects brought on by the constant and rhythmic drone of Tibetan Buddhist chants that transport the monks and even other listeners into realms of blissful meditation.

Brain wave entrainment is a real phenomenon and is useful as one method of investigating how the brain works. But there is no evidence, nor any theoretical basis, for any long lasting effect on brain function or that there is any benefit of any kind. Despite this, there is a huge industry of devices that claim to train your brain waves and have a beneficial effect. I wouldn’t waste a dime on any such device.
But what would be the point of generating a beat that was at the same rate as a certain brainwave frequency? First, consider that these frequency bands relate to different states of awareness. Delta is seen in deep sleep, theta in lighter stages of sleep, alpha when we are relaxed with eyes closed, and beta when we are awake and alert. Second, the main idea behind using binaural beats to help a person relax and sleep is that of entrainment. Entrainment means that a biological process is matched to some external stimulus. For example, our circadian clock is entrained to the day/night light cycle and helps the body organize physiological processes in an appropriate way over the course of the day. A repetitive sound at the frequency of a certain brainwave band could theoretically cause the brain waves to be entrained to that frequency and thus help induce the state associated with that brainwave band. This could have therapeutic utility.

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.

Cortisol is an arousal hormone, stimulating alertness and attention. Cortisol levels rise and fall in connection to circadian rhythms—cortisol levels rise to their peak levels first thing in the morning, just in time for you to be active for the day. Too-high cortisol levels are associated with insomnia, as well as more time spent in light sleep, rather than deep sleep.
A therapy that slows brainwave activity, helping to produce low-frequency waves, is likely to aid relaxation and sleep. But it’s not only lowering brainwave frequency that binaural beats may offer to sleep and relaxation. A small study (19 people) has found that exposure to binaural beats is associated with changes to three hormones important to sleep and well being:
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.
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.
The brain has two hemispheres that operate somewhat independently from one another. The two hemispheric structures of the brain are connected by a large nerve, called the corpus callosum, which sends information back and forth between the two sides of the brain. In most people, the left hemisphere controls language, logical thinking, and analytic processes and the right side contains the centers for emotion, intuition, and non-linear creative thinking.
In addition to potentially boosting sleep-promoting hormones, binaural beats may also reduce our perceptions of pain. A 2017 study found binaural beats used in combination with visual stimulation led to reductions in patients’ perception of acute pain. Other recent research showed binaural beats helped improve pain perception in patients with chronic pain.
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.
You may have experienced Theta right before drifting off to sleep, during a lucid dream, or during a deep meditation. In Theta, you no longer sense the outside world, but you are aware and conscious of your internal world. All of your subconscious fears, hopes and judgments are hidden in the Theta state. Theta is a difficult state to achieve because you often drift out of it very quickly either becoming conscious in Alpha or moving on to the next deeper state. By staying in Theta, you can learn endless information about yourself and your consciousness.