Other entrainment methods sometimes used include autopan modulation that moves sound in an 180º arc to create a desired tone. Harmonic box entrainment, invented by James Mann, uses a layering of binaural and monaural tones that alternate between ears, requiring headphones. Sound modulation and filtering, amplitude modulation, and pitch panning use diverse sounds to create rhythmic pulses matched to the desired brainwave frequency. 
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!?
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.

Binaural beats require two separate tones from two sources that are combined inside the listener’s brain to form the target tone. The lower frequency sound is called the carrier tone, and it is combined with a higher frequency sound known as the offset tone. Because of this, binaural beats must be listened to with stereo headphones or the effect is lost. Binaural beats create a hypnotic effect, but they are not the most effective tool for brainwave entrainment, and binaural beats are often ineffective for people with hearing loss.
The name of the game (and by game, we mean mind hack) is binaural beats. Binaural beats refer to the event in which two similar — but not identical — frequencies are played in different ears through headphones. For example, you might have a 300 Hz tone playing into your left ear, and a 305 Hz tone playing into your right ear (hence the need for headphones, since it’s important for the different sounds to be heard in isolation). Your brain will hear those two tones, yes, but what it will also pick up a 5 Hz tone – the difference between the two frequencies – which is actually too low for our ears to hear. So what’s happening here is not that your ears are suddenly picking up a tone that they couldn’t prior, but instead, your brain is producing the tone; you are perceiving it, not actually hearing it. The resulting noise that you will hear is a steady rhythm, about 4.5 beats per second. Your brain, in the process, will actually emit brainwaves at the frequency of the synthesized tone.
Therefore we are very receptive to new technology products that promise to improve our lives, or solve previously difficult problems, because of some new scientific or technological advance. This has created, in a sense, a marketplace of consumers that expect to be dazzled with technobabble they don’t understand, backed by assurances of legitimacy by the citing of research and association with professionals or professional institutions, and offering significant benefits. We are all, in a sense, waiting for that next product to improve our lives, and many of us like to feel we are on the cutting edge – getting an advantage over others by being savvy early adopters.
Another uncontrolled study asked eight adults to listen to a binaural beat CD with delta (1 to 4 Hz) beat frequencies for 60 days straight. The participants filled out surveys before and after the 60-day period that asked questions about their mood and quality of life. The results of the study found that listening to binaural beats for 60 days significantly reduced anxiety and increased the overall quality of life of these participants. Since the study was small, uncontrolled, and relied on patient surveys to collect data, larger studies will be needed to confirm these effects.

You may recognize the "binaural recording" from ASMR, where the technique is often used. This explains why, if you search for "binaural" on YouTube, you get a mixture of two entirely different kinds of results: binaural beats and binaural ASMR recordings. It gets especially confusing in that there's some questionable and/or unexplored science surrounding each one.
The I-Doser claims it can emulate prescription drug-like effects by listening to MP3's, to get stoned.[1] This is largely a moral panic by parents who flunked science fueled by the eternal quest by teenagers to get stoned, and stupid ones convincing their friends it works. It is really more of wishful thinking and making yourself disoriented by playing discordant sounds really damn loud. If you want to experience it yourself, you can always listen to Bjork Captain Beefheart dubstep.
By the 1980s, entrainment technology had merged with advancements in microelectronics technology, making it possible to develop even more sophisticated audio and visual brainwave entrainment products for the marketplace. In the last two decades, a number of scientific studies have reported brainwave entrainment as an effective remedy for ADD, academic learning problems, and improving memory and cognition.
A person driving on a freeway, who discovers that they can't recall the last five miles, is often in a theta state - induced by the process of freeway driving. This can also occur in the shower or tub or even while shaving or brushing your hair. It is a state where tasks become so automatic that you can mentally disengage from them. The ideation that can take place during the theta state is often free flow and occurs without censorship or guilt. It is typically a very positive mental state.
From a brainwave entrainment effectiveness perspective, it’s my understanding that the response from isochronic tones stimulation starts to diminish over 30Hz and that 40Hz is about the limit for using them. So from what I’ve read on the topic a 100Hz beat wouldn’t work, probably because it’s too fast for the brain to process and synchronise with it.
I just want to write another email about how happy I am with your product, Equisync I, or the alpha waves. I dont think I have ever been so relaxed in my entire life. When I get sink into the state, it feels like a huge electric blanket is pulsing through my body, a really warm, swirling feeling, and my mind is very inactive. I am a meditator without your product. I am able to enter witness consciousness fairly easy on my own sometimes during the day in activity. This isnt the heart oriented feeling of bliss or expansion, but it still is great for the body/mind. This is great though, as it seems to fully relax me. I still believe, that for one to really see dramatic results, meditation should be a way of life. Considering how many of us, spend most of our day unconscious, not aware of the witness or the self, an hour a day is better than nothing, but would be best to be proactive during the day, watching. Keep up the great work and thank you for your product and research.
It has been both a pleasure and an enlightening experience listening to the Equisync II CDs for the past month. As a 15 year stroke survivor, daily meditation has become a part of my life. Listening to these CDs reminds me of sitting alone in a forest during periods of rain, whether they be light, heavy, or in between. I am able to access my right hemisphere more readily and experience the feeling of nirvana that we all have within us. When I reach this point, my system reminds itself of all the compassion and connectedness we each have.
Sleep issues are becoming much more of a common problem. I think it's great to look at alternative ways to help with insomnia and other sleep related issues, especially when they don't involve the need to take medication. Something proved to be effective is 'Sleepstation' a UK based organisation who use CBT techniques to cure insomnia. Their online sleep therapy course is brilliant and very convenient as it's delivered online. Their website is definitely worth a look if you're having sleep issues
Sit in easy pose or posture with a straight spine. Bring arms comfortably to the sides of the body with the elbows bent. Hands in fists with the thumb over the last three fingers, facing forward. Forefinger or Jupiter finger up straight. Hold the Jupiter finger very straight, tight and stable, without tensing the rest of the arms and body. The forearms should be perpendicular to the ground. During the meditation check the position and move the elbows forward as needed to maintain the position.
From a brainwave entrainment effectiveness perspective, it’s my understanding that the response from isochronic tones stimulation starts to diminish over 30Hz and that 40Hz is about the limit for using them. So from what I’ve read on the topic a 100Hz beat wouldn’t work, probably because it’s too fast for the brain to process and synchronise with it.
This blog was created from an interview with Joseph Kao, creator of iAwake’s Journey to the Center of the Self, and iAwake’s CEO John Dupuy, by Heidi Mitchell, who has been working with John for 11 years as assistant and editor. John introduced her to Integral theory and practice and brainwave entrainment enhanced meditation in 2007. Heidi is also a freelance editor of nonfiction books, blogs, and web sites. She can be reached at www.heidimitchelleditor.com.
If brainwave entrainment leaves you with unwanted side-effects (see below) or discomfort, you’re probably encouraging a range of brainwaves that are already excessive in some area of your brain. The way around this is to get a brain map to see what your brain’s strengths and weaknesses are, and see what (if any) brainwaves could use some encouragement. 
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.

Some studies have found that binaural beats can affect cognitive function positively or negatively, depending on the specific frequency that’s generated. For example, a study of long-term memory found that beta-frequency binaural beats improved memory, while theta-frequency binaural beats interfered with memory. This is something for scientists to continue to examine closely. For people who use binaural beats, it’s important to understand that different frequencies will produce different effects.
The gentle pulsating rhythms of Brain Sync audio programs act in a similar fashion, yet because the frequencies are precise and consistent they can be targeted to induce highly specific and desired brain states. Just as you can tune a radio to get a particular station, with Brain Sync technology you can re-tune your consciousness – effectively dialing your mind into a wide variety of brain states.

In Theta, you are in a waking dream, receptivity is heightened and you are able to access knowledge and information that normally lies beyond your conscious awareness. As flashes of vivid imagery dance before your mind's eye, you may feel a "floating" sensation as your mind expands beyond the boundaries of your body. In this deeply relaxed state don't be surprised to receive sudden insights, inspiration or a sense of knowing.
a concise P.S. I was in a horrible car accident when I was 18 and had to learn to read and write and walk and talk all over again. It was long ago and I’m pretty well over it, but such an injury has lifetime repercussions. The neurological damage sustained causes my left arm to shake uncontrollably anytime I use it in a situation requiring precise coordination. From simply listening to the demo, the shake [though not disappearing completely in the last 2 months] has lessened dramatically. I had been wondering for years what kind of neurological exercises I could undergo to help it…
If you search the Internet for "binaural beats" you'll quickly find there's a whole industry built on the idea that listening to binaural beats can produce all kinds of desired effects in your brain. It can alter your mood, help you follow a diet or stop smoking, get you pumped up for a competition, calm you down, put you to sleep, enhance your memory, act as an aphrodisiac, cure headaches, and even balance your chakra. Binaural-Beats.com offers a $30 CD that they call the world's first "digital drug". They claim it can get you drunk without the side effects. I-Doser.com offers a range of music tracks that they say simulates a variety of actual pharmaceuticals, such as Demerol, Oxycontin, and Vicodin. Suffice it to say that no matter what superpower you're looking for, someone on the Internet sells a binaural beat audio file claimed to provide it.