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, 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.
Brainwaves, or neural oscillations, share the fundamental constituents with acoustic and optical waves, including frequency, amplitude and periodicity. Consequently, Huygens' discovery precipitated inquiry into whether or not the synchronous electrical activity of cortical neural ensembles might not only alter in response to external acoustic or optical stimuli but also entrain or synchronize their frequency to that of a specific stimulus.
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.
Our products are gluten and dairy free. Most of our products are also free of soy and corn. The exception would be any formulas that contain cornsilk, including UTI Urinary, Growing Pains for Kids, Herbal Cal, and Kidney Strengthener. Catnip Oil Bug Spray contains soybean oil. Our Ear-Be-Well Ear Oil, Oh Baby! Oil, and Pregnant Belly Oil do contain almond oil.
^ Bittman, B. B., Snyder, C., Bruhn, K. T., Liebfreid, F., Stevens, C. K., Westengard, J., and Umbach, P. O., Recreational music-making: An integrative group intervention for reducing burnout and improving mood states in first year associate degree nursing students: Insights and economic impact" International Journal of Nursing Education Scholarship, Vol. 1, Article 12, 2004.
Many people experienced in using alpha brainwave entrainment report that the state of mind associated with alpha waves is a time when they feel most consciously connected to their subconscious mind. The intense experience of hypnagogic sleep, reported by some people as a feeling of being awake and asleep at the same time, is also associated with alpha brainwaves.
Business executive and radio producer Robert Monroe started experimenting with brainwave entrainment and has a series of powerful out of body experiences using it. In 1971 he published his cult classic “Journeys Out of the Body” sharing his experiences. He later created one of the first audio entrainment companies called Hemi Sync, alongside the Monroe Institute of Applied Sciences.
Synchronized brain waves have long been associated with meditative and hypnogogic states, and audio with embedded binaural beats has the ability to induce and improve such states of consciousness. The reason for this is physiological. Each ear is "hardwired" (so to speak) to both hemispheres of the brain (Rosenzweig, 1961). Each hemisphere has its own olivary nucleus (sound-processing center) which receives signals from each ear. In keeping with this physiological structure, when a binaural beat is perceived there are actually two standing waves of equal amplitude and frequency present, one in each hemisphere. So, there are two separate standing waves entraining portions of each hemisphere to the same frequency. The binaural beats appear to contribute to the hemispheric synchronization evidenced in meditative and hypnogogic states of consciousness. Brain function is also enhanced through the increase of cross-collosal communication between the left and right hemispheres of the brain.
Summaries from recent reviews on yoga or Tai Chi clinical trial interventions indicate that these mind-body types of exercise can be effective in reducing stress (7,14,17). The authors of these reviews suggest that the results should be viewed with caution because study quality was varied (7,17). However, it should be noted that reductions in stress reported in one review were similar to or greater than reductions from other types of commonly used stress management techniques (7).
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.
One RCT (n=108) showed significant reduction in anxiety from a single session of alpha/delta therapy for day surgery patients. A crossover RCT of a single session of theta stimulation in four healthy adults reported significant improvement from the intervention in one of five measures. Five pre/post studies reported significant benefit from the intervention for 16 of 27 outcomes.
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.
Brainwave entrainment music can be used almost anywhere and anytime, making this mood and self-improvement method versatile and flexible enough to do at work, while traveling, or at other times during the day. When used in the workplace during short rest periods, brainwave entrainment techniques can enhance concentration, communication, and work productivity.
While the physiological and psychological processes being uncovered by brain science in the study of brainwaves is sometimes complex and still being investigated, certain basic principles are well-established, easily understood, and helpful for achieving the most effectively use of brainwave entrainment when seeking relaxation, improved sleep, lowering of anxiety, or other goals. This important background information and scientific knowledge presented here includes: