A newer alternative to binaural beats is isochromatic tones. These are tones that are interspersed with periods of brief silence, creating a similar effect to binaural beats but without the two frequencies playing in different ears. Because isochromatic tones do not need headphones, they are gaining popularity as the newest method of brainwave entertainment.

♥ I've suffered from patches of insomnia throughout my life, extending from a few days to dragging on for several weeks, and no amount of the usual proper "bedtime ritual" normally recommended, calms me, as my brain is overactive. Layering combos of the Binaural/Bilateral sounds right before sleep effectively resets me, allowing me to sleep like a normal human. I can't express enough gratitude!
Entrainment is a term originally derived from complex systems theory, and denotes the way that two or more independent, autonomous oscillators with differing rhythms or frequencies, when situated in a context and at a proximity where they can interact for long enough, influence each other mutually, to a degree dependent on coupling force, such that they adjust until both oscillate with the same frequency. Examples include the mechanical entrainment or cyclic synchronization of two electric clothes dryers placed in close proximity, and the biological entrainment evident in the synchronized illumination of fireflies.[13]

It has been scientifically verified that if you consistently listen to binaural beats, for example, that are beating between 7hz-13hz, your brain will naturally tune in to that hz level and bring you to the alpha level (which as mentioned at the beginning is roughly between 7hz-13hz). This is called frequency following response or brainwave entrainment*. Taking it a step further, if you listen to binaural beats that are between 4hz-7hz your brain will adjust to the theta level, and you may experience deep meditation, or lucid dreaming (dreaming while conscious), or even astral projection (when you listen to the binaural beats daily, giving your brain time to build new neuro pathways). By listening to binaural beats that are below 4z you may totally zone out and lose all body awareness as you plung into the delta level. Or, to improve memory, binaural beats are made at about the 16hz-24hz range (well into the beta range). And so on and so forth.
At the beginning of May, I decided to change over to EquiSync because it’s much cheaper and let me experience the deeper levels sooner. At best, my blood pressure has been down to 66 and after cups of tea and food, back up to 76-80 which is regarded as acceptable. I was able to achieve these wonderful results in less than 6 months of daily practice of meditation using audio-beat technology.
4. Theta State: (4 — 8Hz) We're able to begin meditation. This is the point where the verbal/thinking mind transitions to the meditative/visual mind. We begin to move from the planning mind to a deeper state of awareness (often felt as drowsy), with stronger intuition, more capacity for wholeness and complicated problem solving. The Theta state is associated with visualization.
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.
Sleep is something that many people take for granted, but since it takes up about one-third of our lives, it’s worth considering carefully. Besides the obvious benefit of providing time for cell regeneration and repair, eight hours of regular, sound sleep sets you up for optimal functioning of mind and body. It strengthens your immune system, improves your mood, and sharpens your alertness and powers of attention. Getting sufficient sleep lowers your risk of high blood pressure, heart disease, obesity, and diabetes, and it makes you less susceptible to accidents. 
A few months ago I decided to test the ability of the “Equisync II” brainwaves therapy combined with other more traditional self-improvement programs and the results have been even more amazing to me. Currently in my mind I honestly believe this type of therapy can be a breakthrough, or simply the genesis of a new type of therapeutic techniques to correct several psychological, and behavioral human issues including depression, lack of organization, and self-esteem among many, many other possibilities.
3. Alpha State: (9 — 13Hz) Brain waves start to slow down out of thinking mind. We feel more calm, peaceful and grounded. We often find ourselves in an “alpha state” after a yoga class, a walk in the woods, a pleasurable sexual encounter or during any activity that helps relax the body and mind. We are lucid, reflective, have a slightly diffused awareness. The hemispheres of the brain are more balanced (neural integration).
Then in my own research regarding my life-long hypertension and its resistance to medication, I became very concerned when I learned that 145/95 is the gateway to dementia. At that time my BP was consistently 145/95. Then, even worse, it started to become routinely 161/106. I was simply unwilling to take more medication with all its attendant side effects, so I started researching natural solutions. I became aware of a breathing apparatus which sold for $300 that would help me train myself to deep breathe, thereby reducing my blood pressure. $300 seemed like a lot, but not in the scheme of saving my life. I started thinking. I already knew how to breathe from my brief studies in Chi Gung. I simply needed something to help me focus my mind. I tried using the Chi Gung breathing while simply counting 200 breaths. It worked for a short while, but I quickly became far too bored, even though I knew it could be a lifesaving measure. I had been considering EquiSync for sometime, and realized it was much less expensive than a $300 breathing regulator, and that it might serve a dual purpose. So I purchased the entire suite.
... [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. ...
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.
Known as audio-visual brainwave entrainment, or AVE, this method involves the simultaneous flashing of light and audible, rhythmic tones using specialized equipment such as the Mind Machine. Also known as the Dream Machine or psycho-Walkman, this lightweight headset lets you experience a wide selection of audio and visual entrainment tracks while having complete mobility.

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.
That is generally where the science ends and the pseudoscience begins. A number of companies and individuals have then extrapolated from the phenomenon of entrainment to claim that altering the brain waves changes the actual functioning of the brain. There is no theoretical or empirical basis for this, however. Entrainment is a temporary effect on the synchronization of neuronal firing – it does not improve or increase brain functioning, it does not change the hardwiring, nor does it cure any neurological disorder. There is no compelling evidence for any effect beyond the period of entrainment itself.
Theta is an ideal state for super learning, storing information in long term memory, re-programming your mind, dream recall, and self-hypnosis. The theta frequency is recognized as the gateway to learning and memory. What is learned in theta get's stored in long term memory. Children under the age of 5 learn more in their first few years of life, because they are primarily in the theta state.

The human body makes for a fascinating body of study. The brain which controls it is even more so. All this while, we viewed meditation as an immeasurable quantity which it is. But many recent studies could figure out a coherent manner to display its effects. And, the scientific benefits of meditation could be fathomed from it putting to rest the viability of meditation. Learn about the workings of the brain above and become more aware of your meditation process.
Binaural beats are an auditory illusion where two oscillators, slightly detuned from each other, are played simultaneously with one perceived by each ear. The human brain mixes the audio from each ear, and the listener perceives a "beating" effect that isn't actually there. This is a well-studied phenomenon that has gained the interest of audiologists and neurologists, but it's most famous for being picked up by the alternative medicine community as a way to get high.
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.
♥ I'm a tired law student always looking for a study boost. I like to put on the Alpha waves and mix this with classical music for research and writing. The "beats" help to drive the music and add a feeling of focus and energy even during slower/softer passages. If you get the levels matched properly, you never even hear them. Throw in a cup of coffee and you'll be ready to save the world. Cheers!

Since opening their online store in 2011, Binaural Beats Meditation has served “hundreds of thousands” of customers, according to James Matthews, the site’s customer happiness manager. “We continue to see an increase in interest… from individuals, but increasingly so from therapists using the music to help clients, health and wellness organizations, and businesses around the world.”

I can’t thank you guys enough for saving my life. I tell everybody I know about your guys. I love you guys. I word of mouth advertise and give my testimony to the power of your technology almost everyday. I am only 30 years old, but since I was 17 teen years old my life was a miserable roller coaster ride. I ended up being diagnosed with fibromyalsia, bipolar disorder, adhd, manic depression, sever anxiety, severe depression, chronic fatigue syndrome, and you name it. Because of your product, I have never felt better in my entire life. I can cope and manage and more. I can finally sleep a full night without tossing and turning waking to knots in my back and stomach. I can finally stand straight and tall without feeling like I have a pinched nerve in my neck. I have energy again, and a renewed passion for life!
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.
Brainwave entrainment is also known as brainwave synchronization.  According to Wikipedia  brainwave entrainment is “any practice that aims to cause brainwave frequencies to fall into step with a periodic stimulus having a frequency corresponding to the intended brain-state (for example, to induce sleep), usually attempted with the use of specialized software.”
Why is exposure to these soundwaves helpful to sleep and relaxation? Science shows that exposure to binaural beats can create changes in the brain’s degree of arousal. Listening to these sounds that create a low-frequency tone, research indicates, triggers a slow-down to brainwave activity—and that may help you relax, lower your anxiety, and can make it easier for you to fall asleep and sleep more soundly.

Brainwave Power Music dedicates ourselves to creating original sound therapy music, using unique Musical Compositions, Binaural Beats and Isochronic Tones as our primary sound elements mixed with different instruments and soundscapes to create a relaxed audio environment. We have one main goal: To help others through our music, be it for physical, emotional, mental or spiritual purposes. We constantly upload new music, and continue to work hard to provide new quality music for everyone.

Binaural beats are created when two tones are played simultaneously, one in each ear. As long as the difference between the two frequencies is less than 30 hertz, the brain perceives the difference in the tones as a “beat” which, if listened to with enough focus, the brain will begin to follow (this is known as the “frequency following response”). By changing the difference between the two beats, the brain will change its wavelength and enter into different “states” of being.

When we are mentally active various groups of neurons will be firing and the EEG will look like a jumble of different waves at different frequencies. When we are in a relaxed state, however, our brains settle into a steady rhythm – when fully awake this is the alpha rhythm, which as a frequency of 8-12 hz and other recognizable features. When drowsy our brainwaves slow to the theta range, 6-7hz, and when in deep sleep into the delta range, 4-5hz.
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.
Slightly higher-frequency entrainment can lead to hyper suggestive states of consciousness. Still higher-frequency EEG states are associated with alert and focused mental activity needed for the optimal performance of many tasks. Perceived reality changes depending on the state of consciousness of the perceiver (Tart, 1975). Some states of consciousness provide limited views of reality, while others provide an expanded awareness of reality. For the most part, states of consciousness change in response to the ever-changing internal environment and surrounding stimulation. For example, states of consciousness are subject to influences like drugs and circadian and ultradian rhythms (Rossi, 1986; Shannahoff-Khalsa, 1991; Webb & Dube, 1981). Specific states of consciousness can also be learned as adaptive behaviors to demanding circumstances (Green and Green, 1986).  
Thanks for your compliment on my article. 🙂 There are some frequency lists which reference and quote some links to metabolism, but I don’t know how effective or reliable that information is. One of the good things but also a drawback of this technology is how accessible it is to use and create tracks. That makes it unattractive for big companies to invest in large-scale research because it’s hard to patent and protect any product they produce based on the research. As soon as they released the frequency data, people like me would produce free videos and cheap MP3s to utilise the research, so they wouldn’t be able to get a good return on their research investment. So to try and gain some insight into what is working for people, at the moment, we are relying upon assessing anecdotal feedback in many areas. Before buying any products/tracks for increasing metabolism, I would look for and try out free videos on YouTube first, to try and gauge how those particular tracks and frequencies work for you.
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.
There’s also some new stuff I’ve certainly never included in tracks before including some gentle pink noise and brown noise blended together in the background with what’s called phase modulation. This is almost outside of awareness as you’re listening to it. This is how your ear tells what direction a sound is coming from. Does it arrive at your left ear slightly before your right ear? You can modulate that. So, again, it has a very gentle, imperceptible rhythmic quality to it.
Sound and light are the most popular methods to entrain the mind, yet there are a few other options in our toolbox. Using vibrational energy from sources such as magnets and electricity has been proven to help overcome addictions, depression, and even treat neurological disorders such as Parkinson’s. In this section, we cover these alternative forms of brainwave entrainment.
It may be that you had the volume too loud, but I would expect you to hear the effects of that straight after you’ve stopped listening, not on a day you haven’t used them. It might be something similar to muscle memory, where you suddenly remembered the sound and sensations it gives you as if you were hearing it again. I don’t know how long you’ve been using this type of thing for, but maybe it’s something that will settle down and disappear once you become more accustomed to the sound.
Hi Rona, thanks for your compliments on my videos and the music I use, I’m pleased you’ve found them helpful. Regarding the pulse-like sound you’ve been hearing, I’ve never had anyone report something similar to that before. I also haven’t heard anyone on brainwave entrainment forums mention it. That is very unusual and because I’ve never come across it before, I’m afraid I don’t know what would cause that.
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.
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]
When tuning instruments that can produce sustained tones, beats can be readily recognized. Tuning two tones to a unison will present a peculiar effect: when the two tones are close in pitch but not identical, the difference in frequency generates the beating. The volume varies like in a tremolo as the sounds alternately interfere constructively and destructively. As the two tones gradually approach unison, the beating slows down and may become so slow as to be imperceptible. As the two tones get further apart, their beat frequency starts to approach the range of human pitch perception[1], the beating starts to sound like a note, and a combination tone is produced. This combination tone can also be referred to as a missing fundamental, as the beat frequency of any two tones is equivalent to the frequency of their implied fundamental frequency.