All you need to experiment with binaural beats is a binaural beat audio and a pair of headphones or earbuds. You can easily find audio files of binaural beats online, such as on YouTube, or you can purchase CDs or download audio files directly to your mp3 player or other device. As mentioned earlier, for a binaural beat to work, the two tones have to have frequencies of less than 1000 Hz, and the difference between the two tones can’t be more than 30 Hz.
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.
Studies have shown binaural beats may affect levels of dopamine, a hormone that plays a broad role in cognition and a particular role in creative thinking. This has scientists examining the possibility that binaural beats can be used to stimulate creativity. (If you’re looking to be more creative and innovative in your thinking, keep in mind that sleep itself is a powerful tool!)
There is a lot to like about this technology as a potential treatment for sleep problems. It’s low impact and non-invasive, it doesn’t rely on chemical drugs, it’s inexpensive and for most people likely easy to adopt and maintain. In this way, it’s similar to the other behavioral therapies for sleep that I like so much, including meditation and relaxation techniques, and other mind-body therapies.
But the notion of changing brain waves is a very appealing one, from a marketing stand point. People can visualize brain waves and we like synchrony. Also, in the computer age, we understand the notion of “programming.” We also have been prepped for the future by movies such as The Matrix, where people could master Kung Fu in minutes by simply “downloading” the knowledge. This gives the whole notion a superficial plausibility. But the science just isn’t there.
"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 was recently asked a question by my nephew, regarding binaural beats. Because of my involvement with meditation and relaxation techniques, he felt comfortable asking about the safety of it and what it was, exactly. I provided him with some information that I felt would assist him in his choice, as to whether or not to listen, and I decided to do a little more research on the subject, in order to better educate myself. I know a little about the topic, but I wanted to know more about it.
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.
Uses of audio with embedded binaural beats that are mixed with music or various pink or background sound are diverse. They range from relaxation, meditation, stress reduction, pain management, improved sleep quality, decrease in sleep requirements, super learning, enhanced creativity and intuition, remote viewing, telepathy, and out-of-body experience and lucid dreaming. Audio embedded with binaural beats is often combined with various meditation techniques, as well as positive affirmations and visualization.

Binaural-beat perception originates in the inferior colliculus of the midbrain and the superior olivary complex of the brainstem, where auditory signals from each ear are integrated and precipitate electrical impulses along neural pathways through the reticular formation up the midbrain to the thalamus, auditory cortex, and other cortical regions.[6]

Go behind the scenes of brainwave entrainment technology creation with Joseph Kao, developer of the extraordinary meditation tool Journey to the Center of the Self. Here, in an interview with John Dupuy, CEO of iAwake Technologies, Joe describes the amazing complexity of the brainwave entraining soundscape he created to both accompany his deeply inductive, 30-minute, guided meditation on the first track of Journey, and also stand alone as a music-only track that holds you in a profoundly relaxed, still, yet clear place on the theta/delta border. To find out all that went into the making of the inductive guided meditation on the first track of Journey, see A Guide to Transpersonal Meditation: Journey to the Center of the Self, part I of this interview.

Thanks for your appreciation of what I’m doing. I’ve been asked for help with autism a number of times over the years, so it’s something that I’ve often looked into and tried to find new information about. Unfortunately, I’ve yet to find any specific research relating to it and using the type of brainwave entrainment tones I use. There are a number of opinions and claims out here, but I’ve often found them to be conflicting. While some are recommending higher frequency gamma waves, others are recommending lower frequency alpha and theta waves while meditating.
The aim of this study is to identify tendencies in the effectiveness of relaxing audio stimuli that could be verified through further focused experiments. A series of brainwave entrainment (BWE) techniques for inducing relaxation will be presented consisting of different binaural phenomena (BP). The BP will derive from the binaural sine wave beat, widely acknowledged in rhythmic BWE... [Show full abstract]
Passively listening to binaural beats may not spontaneously propel you into an altered state of consciousness. One's subjective experience in response to binaural-beat stimulation may also be influenced by a number of mediating factors. For example, the willingness and ability of the listener to relax and focus attention may contribute to binaural-beat effectiveness in inducing state changes. "Ultradian rhythms in the nervous system are characterized by periodic changes in arousal and states of consciousness (Rossi, 1986).
The authors concluded that preliminary evidence suggested that brainwave entrapment was an effective therapeutic tool, but further research was required. The evidence presented appeared to justify the recommendation for further research. In view of the lack of controlled evidence and problems with methodology and reporting in the review, the authors’ conclusions regarding efficacy did not appear reliable.
In the meta-analysis performed by Fox et al., several sources of bias were indicated which bring into question the validity of meditation studies which use neuroimaging. Fox et al. suggests a publication bias may be leading to the over-reporting of significant results.[18] Despite this, however, Fox et al. found "consistent differences in prefrontal cortex and body awareness regions" in "areas key to meta-awareness..., exteroceptive and interoceptive body awareness..., memory consolidation and reconsolidation..., self and emotion regulation..., and intra- and interhemispheric communication..." and that changes were significant with "moderate" global median effect size and "consistent and medium-sized brain structure differences."[18]

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.
Effects on cortisol: The hormone cortisol is commonly associated with stress, and when levels are higher than usual, it can have a negative impact on the body. High levels of cortisol can lead to a range of conditions, including Cushing syndrome, menstrual cycle and female libido changes, anxiety, and depression. Dr. Giampapa noted a reduction of cortisol of up to 70-80 percent in several study participants.