Subsequently, the term 'entrainment' has been used to describe a shared tendency of many physical and biological systems to synchronize their periodicity and rhythm through interaction. This tendency has been identified as specifically pertinent to the study of sound and music generally, and acoustic rhythms specifically. The most ubiquitous and familiar examples of neuromotor entrainment to acoustic stimuli is observable in spontaneous foot or finger tapping to the rhythmic beat of a song.

When the brain is stimulated with pulsed sounds (neuro-electrical activity via the nerves originating from the ears), the overall activity of the brain will respond to and align with these pulses. By selecting the desired rate, the brain — via the frequency following response (entrainment) — can be naturally induced towards the selected brainwave state.
Another small scale study with 30 children were entrained with a starting frequency of 14 Hz and ramped up to 40 Hz. Following the excitatory-based protocol, they were then given a protocol that started at 40 Hz and decreased to 14 Hz over 6 weeks. The results indicated that the children significantly improved in arithmetic abilities based on the WISC-III.
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?
Most of our Royalty Free brainwave entrainment music uses an audio technology known as "binaural beats". These binaural beats are embedded in the music in order to bring about desirable changes in brainwave activity, thereby encouraging various states of relaxation, deep meditation or sleep. When played with headphones, you may be able to hear the binaural beats as a subtle pulsing sound beneath the music.
At a certain point (generally after about four to six months), your brain will have made all the changes it needs to make to handle the Holosync® we use in Awakening PrologueTM. At that point you’re like a runner who’s been running two miles a day for several months, and now two miles is easy, because the body has created the physical structure that can easily handle it.
Rather than discontinuing my meditation practice altogether, I instead began researching methods of increasing the effectiveness of meditative practice. This seemed an inevitable decision for me in light of the undeniable improvements I had witnessed in response to previous experience with meditation. This resulted in my eventual re-discovery of brainwave meditation programs brainwave synchronization. I had used a few different such products previously, but none that seemed effectively designed to meet my specific needs. After deciding to try a particular brainwave meditation program, I found it to greatly assist me in producing all of the previously experienced benefits of meditation, but in a shorter period of time and in a much more focused manner.
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!
I just wanted to thank you guys for having such an outstanding product available. I used to meditate when I was younger but got away from it over the last 7-8 years. I had difficulty starting back up, but since I started using your cds I have no difficulties getting back into it; and am now meditating 2 hours per day and have never felt better. I have only been using them for a couple weeks but have already noticed a difference. Thanks again for creating such a wonderful product and I will be sure to recommend it to everyone.
I was diagnosed with “acute high anxiety, major clinical depression,and ptsd” 16 years ago. I have clinically addressed these disorders with a number of medications, which none have helped. I am so lucky I have found this simple easy to practice method of practice, that I have found these beats and tones so essential that I indoctrinated them into my daily life, and have come to the realization, that someday very soon I will awake and will not suffer from these burdens these disorders ever again.
When the body-mind effects from experiencing AVE are fully appreciated, the experience becomes as regular and beneficial as many other life essentials such as quality sleep, good nutrition, pure water and exercise. Sleep is another area where AVE has been shown to be beneficial, contributing to the natural regenerative process of the body and brain.
The technology transmits voice messages on close to ultrasonic frequencies that we can not consciously hear, directly into the subconscious mind, with no chance for the conscious mind to filter the information, making it powerful enough for subliminal control. This technology is now available for self improvement purposes with categories such as:  Self confidence, motivation, focus, stress relief, sleep and memory improvement. You can also get your very own custom subliminals to program yourself with anything you want. In 1996, Edward Tilton, President of Silent Sounds claimed that such technology had been used successfully even in military operations to make enemy troops lose morale and surrender. Now we use it for self improvement!
Brainwave entrainment is clearly NOT an effective standalone treatment for mental illness, but it may be an effective adjunct treatment in certain individuals. It should also be mentioned that when using brainwave entrainment, you may want to have a specific purpose in mind. If your goal is to relax, yet you’re using a protocol that is stimulating, you may falsely conclude that it doesn’t work even though you’re using the wrong protocol.
Meditation Begins • Mind Chatter Slows Down • Great For Learning & Studying • Creative Ideas Flow • Reverse Brain’s Aging • Habits, Fears, Phobias Melt Away • Calm & Peaceful • First Layer Of Subconscious Mind • Gateway To Deeper Mental States • Advanced Focus • Relaxation Begins • Serotonin • Endorphins • Good For Anxiety, Depression, Stress, Panic • Mind Power • Happiness • Confidence
I first became aware of brainwave meditation programs  and brain waves when researching alternative methods for treating the bipolar disorder I had been unsuccessfully living with my entire adult life. I eventually learned a method of releasing difficult emotions on the spot, which I then practiced extensively, and consequently found it easier and even desirable to meditate for fairly lengthy periods of time. Though I took up meditation as a serious daily practice and experienced many undeniable benefits, I nonetheless intermittently experienced life-debilitating bouts of mania and severe depression, often resulting in chaotic mixed states and an inability to maintain daily social functions. During these times, it became nearly impossible to sit in meditation.
Hi Ulka, thanks for your compliment on my article. Unfortunately, I haven’t come across any studies or much discussion about the problem with habituation and isochronic tones and how to overcome it. The consensus among experienced users is to regularly change the frequencies and music soundtracks you listen to. Adding music to the tones does change the waveform you are stimulated with, so that’s one of the main reasons why I provide different soundtracks for my isochronic tones sessions. I have released some tracks which use amplitude modulations in the music, instead of isochronic tones. It might be worth giving them a try if you haven’t already. I have them in a playlist on YouTube https://www.youtube.com/watch?v=Lj5tHl2cuWw&list=PLveg0IEcZWN6OIRZyLkv0BJADY7Q6xFCl.
Thanks for the coupons, I had originally looked into these cd’s after my doctor recommended them, but my mom wound up buying them for me for Christmas (she didn’t know about the coupons I had!) Anyway just listened to Equisync II today for the first time, I was in such a state as to where I didn’t know if I’d fallen asleep or not! I hadn’t but was in such an amazing place.
There are many advantages and disadvantages with binaural beats. One of the major advantages is hemispheric synchronization. Since both hemispheres are required to create the beat within the brain, this method is an excellent way to create greater harmony between areas of the mind typically functioning independently. Binaural beats are also known to have effective hypnotic and relaxing effects.
When the brain is stimulated with pulsed sounds (neuroelectrical activity via the nerves originating from the ears), the overall activity of the brain will respond to and align with these pulses. By selecting the desired rate, the brain via the frequency following response (entrainment) can be naturally induced towards the selected brainwave state.
* Supports iOS 5.0 and higher * Thanks for making Brain Wave the Top Selling Brainwave Entrainment app 4 years! This update includes improvements to our last major update, which included a ton of new features, including the ability to use your iTunes Music as the background and Alarm Audio, support for running another audio app simultaneously, such as a web or ebook reader, and UI updates for iOS 7.
"I'm not writing with a question, but to THANK YOU for these CDs. I originally bought The Meditation Program with the intention of returning it, believing it to be nothing more than just 'another piece of hype.' Wow, I was wrong. This was the turning point in my life. You gave me strength, and stability, and literally changed everything around. I feel GREAT, and it's thanks to YOU. Thank you, thank you, THANK YOU for The Meditation Program CDs. I am a true dedicated customer of yours!"
* Headphones/Earbuds are Required for Binaural Tones to be Effective as the Left Ear and Right Ear Audio must be isolated for the Brain to perceive the inaudible low-frequency difference between the two sides. ** Changes to Orientation Support: With the upcoming arrival of several new devices with new screen-sizes and aspect ratios, iOS 8 required a re-write of our iPhone and iPad UI to support these devices, and as part of that, we have returned the app to a Portrait-only view for now. Once we know what these future screen dimensions and Aspect Ratios are, and have time to work with the real devices, we can implement a new Landscape UI for the iPad.
Leap over obstacles and hurdles, easily – Nothing worth having is ever easy. Everyone faces problems. The difference is, how you handle those problems. Imagine if you never even see them as problems to begin with... if it's just easy, somehow, to envisage simple solutions to hurdles and enjoy the challenge. Successful people thrive on challenges... you could begin to experience the very same rush!
In the past, the most common method of inducing specific brainwave states was through the use of binaural beats. One specific beat was played in one ear (through stereo headphones) and a different beat was played through the other. What the brain would naturally do in hearing these variated beats was create its own beat from the combination of the two (ie if a beat at 100 Hz was played in one ear, and a beat of 110 Hz was played in the other, the brain would resonate at 10Hz). Aside from this directing the brain into a specific state, it also causes the two hemispheres of the brain to synchronize, promoting whole brain functioning. More recently, other methods have been discovered for inducing specific brainwave states, such as isochronic tones, and monaural beats, but the bottom line is that
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.

One of the most fascinating and beneficial things about Delta brainwaves is their ability to stimulate the release of anti-aging hormones in the body, such as HGH (human growth hormone). Increased melatonin levels are also common in this state, and regular visits to Delta have also been shown to decrease cortisol levels. (Cortisol is a hormone that is released during stressful situations, that has been linked with the aging process.) In a nutshell, Delta brainwaves are very healthy, and until now have only been accessible to us during deep sleep.
While it may not be a perfect therapeutic option for treating certain psychological conditions, brainwave entrainment is yet another tool that warrants further testing and exploration. There is clear evidence that certain protocols may benefit human performance. Unfortunately nearly all of the research has been conducted by those who clearly are affiliated with those who manufacture brainwave entrainment products.
The reported PMS symptoms that improved included: affective lability, anxiety, appetite changes, bloating, breast tenderness, concentration difficulties, depression, fatigue, and irritability. Researchers noted that there was a clear “trend” toward a reduction in social withdrawal as a result of symptoms as well. A total of 49/50 women reported improvements.
I was diagnosed with “acute high anxiety, major clinical depression,and ptsd” 16 years ago. I have clinically addressed these disorders with a number of medications, which none have helped. I am so lucky I have found this simple easy to practice method of practice, that I have found these beats and tones so essential that I indoctrinated them into my daily life, and have come to the realization, that someday very soon I will awake and will not suffer from these burdens these disorders ever again.
If anybody would like to look over the scientific evidence concerning brainwave entrainment and isochronic tones, I’ve done a lot of research over the years which I’ve collected at the PubMed website of NCBI – a branch of the National Institute of Health – that provides access to a large library of medical journal articles. I’ve made my list public so you can look through the journal articles that were published concerning this topic. Here’s the link: http://www.ncbi.nlm.nih.gov/sites/myncbi/1tmDFOl0XtyA4/collections/51531796/public/. Most of the collection only gives access to abstracts or summaries unless you’re at some kind of educational institution that has a subscription to the particular journal that article is in, but I actually find abstracts really helpful. So have at it, read away. And if your psychiatrist/therapist thinks you’re nuts for feeling better after listening to isochronic tones, just whip out your 82-page collection of scientific journal abstracts written by her peers and give it to her to read. 🙂

Because of others observing all of this I have been able to send you several customers and will very likely be sending you more… I am part of a large spiritual community and this would help tremendously in spreading the word of EquiSync. I also believe your product would be of great benefit to Hospice and nursing home patients of which there is a very large number here in Florida -aka- God’s waiting room.

Sleep improvement: There is significant anecdotal evidence that sleep induction and/or quality may be improved as a result of brainwave entrainment. While it is important to consider the placebo effect or simply the effect of a relaxing sound, many people have reported noticeable improvements in their ability to fall asleep and wake up feeling refreshed as a result of entrainment. Entraining frequencies within the slower wave ranges such as alpha, theta, or delta, may help individuals transition more quickly to those states.

In all professionally produced meditation programs, you train your brain gradually. That is how you successfully develop. Just like training the body, you progress gradually. This is the key. In BrainAscend you start with level 1. Each track is 30 minutes.  Use it once per day for 30 or 60 minutes at a time (once or twice in a row. Use repeat/loop function in your player) or twice per day for 30 minutes at a time. You should use every level for at least 2-3 months before moving to the next. The exception is level 1 which is an introductory level which you can use for a week or so. After that time, if you can repeatedly remain fully aware on your current level without falling asleep (even if playing it twice in a row) you can move on to the next level. Until then you should continue on your current level. Listen with closed eyes, either sitting up or laying down.
So discovering the field of Brainwave Entrainment is very exciting and promising. However intriguing, there are a few things that make me a bit sceptical towards it. F.i. I’m not too keen on having to rely on any external stimuli, as (regular) meditation is one of the very few things where you are absolutely independent from anything external to make a change within, which to me makes it so special.
In fact, there is more to answering this question than meets the eye. As someone who’s also been skeptical enough to do the research, I am more than happy to explore the issue in great depth. The important thing to address here is what have you been told that Brainwave Entrainment would do?  Depending on whose site you’ve landed on you may have been promised different things.  The promised benefits of this type of product are a long list, and more things are still being added to it.  You may have been told that brainwave entrainment would help you meditate deeper, and rocket launch your spiritual evolution from doing so.  You may have been told that it would help your brain release positive neuro chemicals and anti-aging hormones that would improve your health and help you feel more positive emotions, overcoming anxiety, and you also may have been told that listening to brainwave entrainment on a regular basis would help your brain evolve, building a higher threshold to mental and emotional input, growing neural pathways, and synchronising the two hemispheres of the brain.

The phenomena of brainwave entrainment was first described in the scientific literature in 1973 by Gerald Oster in results published in an article in Scientific American entitled, “Auditory Beats in the Brain”. He showed that a specific brainwave could be induced when a person heard two separate, but closely related, sound frequencies, one in each ear. He discovered that when the frequencies heard by each ear differed by about 10 hertz, the brainwave pattern of the person hearing the sound would synchronize to the difference between the two frequencies. For example, if the person heard a 410 hertz sound in one ear and a 400 hertz sound in the other ear, their brainwaves would stabilize at the difference between the two, or 10 hertz. This technique is called binaural beats, and it is a fundamental principle of brainwave entrainment methods.
In fact, you can use an audio, as a beginner, that takes your brain to the same places that have been recorded in the brains of 30-year monastic Buddhist monks. When you start doing this, you begin to play around with “benefits” and “effects” that lie solely in the realm of consciousness itself. These benefits are also profound, yet not measurable or provable except through your own subjective experience.
By exposing an individual to repeatedly external stimulus which can be flashing lights and/or recurring sounds, the entrainment process consists in pushing the brain to adjust to match the frequency provided. Unlike other forms of neurotherapy which require the individual to actively respond to stimulus, entrainment creates an immediate neurophysical response which is instinctive and effortless for the person being provided with the light and/or sound combinations. The key outcome of the sensory stimulation is known as the ‘Frequency Following Response’.
In fact, you can use an audio, as a beginner, that takes your brain to the same places that have been recorded in the brains of 30-year monastic Buddhist monks. When you start doing this, you begin to play around with “benefits” and “effects” that lie solely in the realm of consciousness itself. These benefits are also profound, yet not measurable or provable except through your own subjective experience.
BrainAscend is a completely free meditation program featuring 5 deepening levels, meaning 5 free MP3 tracks using brainwave entrainment technology, created by Marcus Knudsen, inventor of BlissCoded sound. It uses the scientifically proven most effective brainwave entrainment technology in a special process that steadily expands your brain power and consciousness level.
Miscellaneous reports have also been made about the advantages of brainwave entrainment with the reviews of numerous users stating that the it can assist in increasing sex drive. Research shows that relaxation, meditation, and good self esteem ensures normal body functions. Furthermore, the brainwave entertainment allows your body to flow in rhythm with the beats therefore if your brain accepts and blends with certain frequencies, this could account for the enhanced sex drive.
The training process allows you to consciously access deeper levels of your brain and consciousness. Your whole brain power and function expands. You become intuitive, relaxed yet focused, creative, your thoughts become clearer and information processing improves more and more. The left and right brain hemisphere synchronizes and you'll start using the full power of your left (analitycal - logical - Intelligence) and right (creativity - imagination - visualisation) hemispheres together. To say that this helps in all imaginable areas of your life is an understatement. You'll also begin to discover deeper realities beyond the physical. You become happier, more relaxed and balanced.

Meditation enhancement: There are several companies that sell brainwave entrainment sessions specifically designed to enhance meditation. The sounds provide a stimuli to focus on during the meditation, and the brain waves naturally shift towards the frequency provided. Whether meditation is actually enhanced by brainwave entrainment is a subject of debate. However, advanced meditators commonly experience brainwave synchronization – which the right and left hemispheres display the same frequency brain waves.  While there are scientific benefits of meditation, it is unclear as to whether they are enhanced, hindered, or unaffected by adjunctive brainwave entrainment.

Leap over obstacles and hurdles, easily – Nothing worth having is ever easy. Everyone faces problems. The difference is, how you handle those problems. Imagine if you never even see them as problems to begin with... if it's just easy, somehow, to envisage simple solutions to hurdles and enjoy the challenge. Successful people thrive on challenges... you could begin to experience the very same rush!


Delta brainwaves have the slowest frequencies, ranging between 0.1 and 4 hertz, and these are the brainwave states associated with deep sleep, trance states, and unconsciousness. Few people can remain awake during delta brainwaves states, although this state is recorded in awake infants between ages of three months and one year and also in babies just before birth. Delta waves are also linked with increased production of HGH, DHEA, and the neuro-transmitter serotonin.

Hi i’m just writing to let you all know that your Equisync CD’s are amazing! Just last night i was meditating to “Equisync II”. The one that has mostly theta binaural beats in it. I gotta tell you i have never had a meditation like i experienced with this CD. At certain points during the meditation it felt like my whole damn body was vibrating! That very night when i went to sleep I also had lucid dreams! It was so relaxing! I’ve tried “Equisync I” too, that one is amazing as well! I haven’t tried “Equisync III” yet. I can only imagine what that is going to be like!
In 1973, biophysicist Dr. Gerald Oster published a famous article in Scientific American titled “Auditory Beats in the Brain”, which found that when two pure tones of varying frequencies were combined, a third rhythmic beat was created which he called binaural or monaural beats. According to Oster, monaural beats occur when two tones are combined and sent through a loudspeaker, while binaural beats occur when stereo headphones are used to deliver each tone separately to each ear. Oster concluded that monaural beats were a more effective form of brainwave entrainment.
Much of what is currently written about brainwave entrainment, especially on the internet, is simply … incorrect.  It seems par for the course that when something of huge value is discovered as a potential ‘internet product’ that it is going to be marketed within an inch of it’s life. And often with less than stellar regard for actual science, research, or factual knowledge. 
At the end of just two weeks of use (I was now into the Equisync II cds), I experienced for the first time ever, what my partner described as Nirvana. I experienced a complete dissolution of individual consciousness, felt at one with everything, and felt the deepest peace, love, and complete bliss I had ever, ever experienced in my life. Since you do all the research on this, you know what I’m describing. Unfortunately, language does not express it. I have never experienced mind altering drugs, but I recall watching a documentary of LSD research, and one of the subjects described the exact same “feelings” as I had when she had received a micro amount of LSD.
If you're struggling to focus and feeling a bit tired and unmotivated while studying, you can help boost your concentration and energy levels by increasing Beta activity.  The SMR range is right at the bottom of the Beta range, so it's not too intense, and so is ideal for playing in the background and using as a general study aid.  If you are looking for something a bit higher for a more intense focus session, try my Study Focus isochronic tones session, which uses frequencies between 14-17Hz.
All brainwave frequencies are useful and beneficial at certain times – there is no brainwave that is intrinsically better than another. However, by deliberately choosing to attain a particular brainwave state, a corresponding mental state can be brought about at the same time. For example, a working person who has been in an overly alert beta brainwave pattern for many hours can quickly shift their mind and body into a relaxed state by listening to a few minutes of brainwave entrainment music for inducing alpha or theta brainwaves.
I typically feel overwhelmed by the numerous things that need to be accomplished, which leaves me feeling anxious and rushed. This particular combo has really helped me to slow down today and not feel so uptight, which sadly, is not easily accomplished. I use other modalities to shift my body into parasympathetic mode, but I can't seem to stay there. This program seems to be helping dampen down triggers that cause my body to shift into sympathetic state inappropriately.

You also may find that after pushing yourself really hard, now you have pushed yourself a little too much, and you’re getting into overwhelm. You may want to ride that overwhelm like a wave to where it’s pushing you just a little bit, but not so much that it will push you over the edge and have you take a dive. So, maybe on Saturday, after pushing hard all week, you might decide to put on the releasing tracks. In this way, you can still experience a very deep and blissful meditation, but without all the push from the carrier frequencies and the biofield amplitude.
So you see, it’s all about where your personal journey is taking you, and what direction of evolution you are wanting to explore.  The purpose of this site is to assist you in making an educated decision about what product is right for you, and to ensure that you are only recommended a high-quality product that will provide you with powerful and noticeable results.  The great news is that many of the benefits of using Brainwave Entrainment (improved sleep patterns, release of anti-aging hormones, whole-brain functioning, etc.) are simply side-effects of using any type of brainwave entrainment audio.
Every NeuralSync™ audio is recorded with full-range frequency sweeps that cycle rhythmically throughout the entire audio. The dynamics of the sweep are then additionally enhanced with simultaneous left-to-right channel crossing. Because of this augmentation, the effects are multiplied, the intensity is amplified and the brain is drawn into the mental state more consistently and powerfully than with the static methods of other protocols.
  1. You'll access powerful states of thought on-demand. When your mind is trained in this fashion, over time, this state of relaxation... the ability to detach yourself from emotional conflict... think creatively and "out the box"... react faster, and more fluidly... and adapt the same powerful, mental modes accessed by the most successful people will become second nature to you. You'll own them as your own.

You also may find that after pushing yourself really hard, now you have pushed yourself a little too much, and you’re getting into overwhelm. You may want to ride that overwhelm like a wave to where it’s pushing you just a little bit, but not so much that it will push you over the edge and have you take a dive. So, maybe on Saturday, after pushing hard all week, you might decide to put on the releasing tracks. In this way, you can still experience a very deep and blissful meditation, but without all the push from the carrier frequencies and the biofield amplitude.
Many psychologists, doctors, teachers, and other professionals have endorsed the technology while personally taking advantage of the limitless benefits that accompany EquiSync's precisely designed brainwave synchronization/ entrainment technology. It is such a profound field of study that many of the metaphysical benefits, those beyond our current scientific measure and technological & philosophical understanding, have yet to be discovered.
Most of our Royalty Free brainwave entrainment music uses an audio technology known as "binaural beats". These binaural beats are embedded in the music in order to bring about desirable changes in brainwave activity, thereby encouraging various states of relaxation, deep meditation or sleep. When played with headphones, you may be able to hear the binaural beats as a subtle pulsing sound beneath the music.
For centuries, brainwave entrainment has been associated with a number of benefits. Of the range of brainwave states that exist there are four frequencies that are the focus of brainwave entrainment; each of these states has a different physiological effect and achieves a different result. What they have in common is the power to trigger your state of mind in order to get a specific outcome.
Creativity: Measuring “creativity” is likely subjective, but many people stuck in a certain dominant brain wave may benefit creatively from shifting the brain wave dominance. Someone who has excess beta waves may fail to relax enough to access certain (potential) creative properties associated with increased alpha waves. Similarly someone stuck in a slow wave state may benefit creatively from increasing beta waves.
Brainwave entrainment represents a way of using technology to take our meditation and our spiritual practices into territory that has previously been very difficult, if not impossible, for us to venture into. My inspiration for creating the Profound Meditation Program 3.0 was not about just adding binaural beats or isochronic tones to music, using conventional audio entrainment methods to create brainwave patterns, and say, “Hey, this is the next big thing!” To me, it is all about what we can do—even if it’s pulling from way outside of the box—to enable such a profound coherence that we can go to meditative depths that have been practically out of reach. With the Profound Meditation Program 3.0, I wanted to do something that hadn’t been done before, taking the technology to the next level.
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 (http://www.mindamend.com/shop/sleeping-and-dreaming/sleep-induction-isochronic-tones/) 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 (http://www.mindamend.com/shop/sleeping-and-dreaming/deep-sleep-8-hour-sleep-cycle/). So it does depend on the individual track you are using.
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