, 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]
"Given the popularity and effectiveness of meditation as a means of alleviating stress and maintaining good health, there is a pressing need for a rigorous investigation of how it affects brain function," says Professor Jim Lagopoulos of Sydney University, Australia. Lagopoulos is the principal investigator of a joint study between his university and researchers from the Norwegian University of Science and Technology (NTNU) on changes in electrical brain activity during nondirective meditation.
I wouldn’t personally recommend listening to delta wave frequencies for depression, so I’m not sure who advised you to do that? People with depression usually have a higher ratio of theta and delta wave activity, so I would normally recommend listening to high alpha wave and low beta wave frequencies, to help balance things. I have some 10Hz alpha tracks for serotonin release, which you can try for free on my YouTube channel here: https://www.youtube.com/watch?v=3NSUcuzpRcY&list=PLveg0IEcZWN6T86nhmSrdwG2kMQtcLRou. I also recommend you give these SMR (low beta wave) tracks a try: https://www.youtube.com/watch?v=HGTvBbrEwZQ&list=PLveg0IEcZWN7yaMaKr8F-eWHALk2_zGqY. I hope that helps.
When I am using equisync I feel kind of like it is “pushing me” – I guess this is the right way to say it- to achieve better results, which I really like. I fall asleep quickly, and sleep all night and even wake up before my alarm goes off. I feel noticeably calm during the workday- which is very helpful for what I do. I really like the warm feeling (my whole body gets really warm during my equisync meditation sessions) and I feel kind of like Im floating while listening. The soothing rainfall is also very nice.
However, yoga and meditation take time to learn and master, and until the student becomes proficient, progress can be slow and frustrating, leading many people to abandon the effort before they see the benefits. Brainwave entrainment has the potential for helping a person enter the relaxing and rejuvenating mind-states brought about by yoga and meditation without the learning curve and time needed for mastering these other techniques. Brainwave entrainment may even facilitate learning other mindfulness methods by helping a person achieve success faster and more reliably. 
John Dupuy is the CEO of iAwake Technologies and travels internationally to teach and inspire on the subjects of Integral Recovery, Integral Transformative Practice, and the use of brainwave entrainment technology to deepen one’s meditation practice and in the treatment of addiction, depression, and PTSD. John is the founder of Integral Recovery® and his book Integral Recovery: A Revolutionary Approach to the Treatment of Alcoholism and Addiction  won the 2013 USA Best Book Award. John also hosts interviews with leading innovators in the spiritual technologies field on Spiritual Technologies 2.0 Live and co-hosts the popular Journey of Integral Recovery podcast.
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.
Binaural beats is a method where two sound waves of different frequencies are introduced into each ear. These frequencies when processed by the brain cancel each other out, creating a whole new frequency. So if we had a tone of 500 Hz in one ear and a 510 Hz tone in the other, the result would be a 10 Hz tone. So while a 10 Hz tone couldn’t be directly heard, using binaural beats we can create that tone inside our brain.
There’s a growing body of research suggesting that binaural beats can reduce different forms of anxiety, from mild to chronic. One especially interesting study looked at the effects of binaural beats on anxiety among patients preparing to undergo surgery—a life circumstance that is pretty anxiety provoking for most anyone. Over a period of six months, patients spent 30 minutes on the day of their surgery listening to binaural beats. Compared to patients who listened to a soundtrack that did not include binaural beats—and patients who received no “beats” therapy at all—the binaural beat listeners experienced significantly greater reductions in their anxiety levels.
Over-arousal in certain brain areas is linked with anxiety disorders, sleep problems, nightmares, hyper-vigilance, impulsive behaviour, anger/aggression, agitated depression, chronic nerve pain and spasticity. Under-arousal in certain brain areas leads to some types of depression, attention deficit, chronic pain and insomnia. A combination of under-arousal and over-arousal is seen in cases of anxiety, depression and ADHD. more...
Hello, I am [name removed], from [city, state removed]. I would like to say thank you for making the CDs. They’ve really helped my friend get over years of abuse and the sadness of loosing the only good friend he had after he moved to [city removed]. I plan on getting the cds for myself, once I get to working, and seeing if they will help me with my problems caused by [condition removed]. But, if you had seen my friend before, and compared it to now you would be amazed.

OK – so some of this is pretty common marketing hype. Consumers have become almost numb to such hyperbole. But still we see some of the common – almost ubiquitous – elements of pseudoscientific scams. The company claims that the device is “effort-free”, that the results are “rapid and long-lasting,” that it is the “most effective” method of its kind, and that it is useful for a broad range of applications (hey, why limit the market). I am used to such hype about dishwashing detergent, but find it intolerable when applied to a pseudoscientific device with medical applications.
I have been using the Equisync CDs at least 24 minutes 5 days a week. It instantly relaxes me, helps get rid of headaches and even hiccups! I have a stressful job and it helps prevent anxiety; I have not had a chance to check my blood pressure but I feel calmer. I have used other products before but I like the Equisync CDs much better; it is deeper and more relaxing.

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
... [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. ...
You don't have to buy one, though. It's not too hard to make your own binaural beat, and free software is widely available to do just that. The one that I used to make that little sample is an open-source program called Gnaural, available on the Sourceforge website. It's pretty easy to use, though it takes some practice before you can generate some of the really cool, more professional sounding beats. A binaural beat consists of two simple tones, and most people add that background pink noise. Nothing special.