The stimulation of human brainwaves is done with sound through binaural beats. While human perceptions of sound ranges from 20 Hz to 20,000 Hz, the frequencies of human brain waves are below about 40 Hz. To get the desired mental wave any sound stimulation is useful always that one sound play in one ear and another in the other ear. For example, if a 315 Hz sine wave is played into the right ear and a 325 Hz one into the left ear, the brain is entrained towards the beat frequency -10 Hz- or the alpha range and in in the same way for the nexts braiwaves.
Binaural beat stimulation has been used fairly extensively to induce a variety of states of consciousness, and there has been some work done in regards to the effects of these stimuli on relaxation, focus, attention, creativity and even intelligence increase. Studies have shown that with repeated training to distinguish close frequency sounds that a plastic reorganization of the brain occurs for the trained frequencies and is capable of asymmetric hemispheric balancing.
The dominant frequency determines your current state. For example, if in someone's brain alpha waves are dominating, they are in the alpha state (this happens when one is relaxed but awake). However, also other frequencies will be present, albeit with smaller amplitudes.
The brain entraining is more effective if the frequency is close to the user's starting dominant frequency. Therefore, it is suggested to start with a frequency near to one's current dominant frequency (likely to be about 20 Hz or less for a waking person), and then slowly decreasing it towards the desired frequency.
Some people find pure sine waves unpleasant, so a pink noise or another background (e.g. natural sounds such as river noises) can also be mixed with them. In addition to that, as long as the beat is audible, increasing the volume should not necessarily improve the effectiveness, therefore using a low volume is usually suggested. One theory is to reduce the volume so low that the beating should not even be clearly audible, but this does not seem to be the case.
In addition to lowering the brain frequency to relax the listener (or to raise it to help focusing), there are other controversial, alleged uses for binaural beats. For example, that by using specific frequencies an individual can stimulate certain glands to produce desired hormones. Beta-endorphin has been modulated in studies using alpha-theta brain wave training, and dopamine with binaural beats.
Among other alleged uses, there are reducing learning time and sleeping needs . Theta waves are thought to improve learning, since children, who have stronger theta waves, and remain in this state for a longer period of time than adults, usually learn faster than adults; and some people find that half an hour in the theta state can reduce sleeping needs up to four hours; however, this is supposed to happen with any way to get into theta state, e.g. meditation; some use them for lucid dreaming and even for attempting out-of-body experiences, astral projection, telepathy and psychokinesis. However, the role of alpha-wave activity in lucid dreaming is subject to ongoing research.
Alpha-theta brainwave training has also been used successfully for the treatment of addictions, for the recovery of repressed memories, but as with other techniques this can lead to false memories.
A trial of Delta binaural beat technology over 60 days has shown positive effect on self-reported psychologic measures, especially anxiety. There was significant decrease in trait anxiety, an increase in quality of life, and a decrease in insulin-like growth factor-1 and dopamine and has been successfully shown to decrease mild anxiety and lessen hospital acute pre-operative anxiety.
Another claimed effect for sound induced brain synchronization is enhanced learning ability. It was proposed in the 1970s that induced alpha brain waves enabled students to assimilate more information with greater long term retention. In more recent times has come more understanding of the role of theta brain waves in behavioral learning The presence of theta patterns in the brain has been associated with increased receptivity for learning and decreased filtering by the left hemisphere. Based on the association between theta activity (4–7 Hz) and working memory performance, biofeedback training suggests that normal healthy individuals can learn to increase a specific component of their EEG activity, and that such enhanced activity may facilitate a working memory task and to a lesser extent focused attention.
Next a summary of binaural beats is presented so you can experiment with each one and share your experiences.
40 Hz +
14 - 40 Hz
8 - 14 Hz
3 - 8 Hz
Deep relax, meditation
0.1 - 3 Hz
Courtesy from mentallion.com