Resources
These resources cite peer reviewed studies, acedemic research projects and professional articles that support the underlying theory and practice of the therapeutic sound system on whatsyourtone.com.
Binaural Beat Technology in Humans: A Pilot Study To Assess Psychologic and Physiologic Effects
Helané Wahbeh, Carlo Calabrese, and Heather Zwickey. The Journal of Alternative and Complementary Medicine. January/February 2007, 13(1): 25-32. doi:10.1089/acm.2006.6196.

The objectives of this pilot study were to gather preliminary data on psychologic and physiologic effects of 60 days daily use of BBT (Binaural beat technology) for hypothesis generation and to assess compliance, feasibility, and safety for future studies.

There was a decrease in anxiety, an increase in quality of life, and a decrease in insulin-like growth factor-1 and dopamine observed between before and after measurements.

Conclusions: Binaural beat technology may exhibit positive effect on self-reported psychologic measures, especially anxiety.

Auditory Beats in the Brain
Dr. Gerald Oster, Scientific American, 1973.

In 1973, Gerald Oster wrote a research article that brought the binaural beat phenomenon to public, mainstream attention and scientific inquiry. He states that slow modulations called binaural beats are perceived when tones of different frequency are presented separately to each ear and that these sensations may show how certain sounds are processed by the brain. He proposed that this phenomenon could be a medical diagnostic tool based on various experiments with neurological conditions and other biological conditions. He concludes that "it is possible that hormonally induced physiological or behavioral changes too subtle to detect by ordinary means may be made apparent by measuring the binaural beat spectrum."

Accessing Anomalous States of Consciousness with a Binaural Beat Technology
F. Holmes Atwater, Journal of Scientic Explorutian, Vol. 1 1, No. 3, pp. 263-274, 1997 0892-33 10197

The Monroe Institute investigates the phenomenon of human consciousness using binaural beat technologies. They have produced numerous studies.

In this study, exposure to binaural beats in an environment of restricted stimulation coupled with a guidance process can safely provide access to and experiences in many propitious states of consciousness. This method requires a unique combination of well-understood psycho-physiological inductive techniques with the addition of a refined binaural-beat technology. Binaural beats provide potential consciousness-altering information to the brain's reticular activating system. The reticular activating system in turn interprets and reacts to this information by stimulating the thalamus and cortex - thereby altering arousal states, attentional focus, and the level of awareness, i.e., the elements of consciousness itself. This effective binaural-beat process offers a wide variety of beneficial applications and vehicle for the exploration of expanded states of consciousness.

A Comprehensive Review of the Psychological Effects of Brainwave Entrainment
Tina L. Huang, PhD; Christine Charyton, PhD. Alternative Therapies in Health and Medicine (2008, September; vol 14:5).

Objective: Brainwave entrainment (BWE), which uses rhythmic stimuli to alter brainwave frequency and thus brain states, has been investigated and used since the late 1800s, yet many clinicians and scientists are unaware of its existence. We aim to raise awareness and discuss its potential by presenting a systematic review of the literature from peer-reviewed journals on the psychological effects of brainwave entrainment.

Findings to date suggest that BWE is an effective therapeutic tool. People suffering from cognitive functioning deficits, stress, pain, headache/migraines, PMS, and behavioral problems benefited from Brainwave Entrainment.

Binaural-Beat Induced Theta EEG Activity and Hypnotic Susceptibility
D. Brian Brady, Northern Arizona University, May 1997

Six participants varying in degree of hypnotizability (2 lows, 2 mediums, and 2 highs) were exposed to 3 20-minute sessions of a binaural-beat sound stimulation protocol designed to enhance theta brainwave activity. The Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C) was used for pre- and post-stimulus measures of hypnotic susceptibility. A time-series analysis was utilized to evaluate anterior theta activity in response to binaural-beat sound stimulation over baseline and stimulus sessions. The protocol designed to increase anterior theta activity resulted in a significant increase in percent theta for 5 of 6 participants. Hypnotic susceptibility levels remained stable in the high-susceptible group and increased significantly in the low and medium-susceptible groups.

The Effects of Alpha (10-Hz) and Beta (22-Hz) 'Entrainment' Stimulation on the Alpha and Beta EEG Bands: Individual Differences Are Critical to Prediction of Effects
Rosenfeld, Reinhart, and Srivastava, Applied Psychophysiology and Biofeedback, Vol. 22, No. 1, 1997.

In this study, two different groups of normal college students were formed. One received alpha (10 Hz) audio-visual stimulation for 8 minutes, and the other received beta (22 Hz) stimulation. Their EEG response was measured before, during, and 24 minutes after the stimulation. In the discussion section of their study, they make the following observation:

The most positive implication of the present findings is that using the presently available, low-intensity stimulations, it is indeed possible in one session to generate EEG changes that may last relatively long after the end of stimulation in some participants. However, perhaps the most important finding of this study was the fact that even the simplest entrainment stimulation (i.e., one frequency for all 8 minutes of stimulation) does not have the same effect on all individuals. The individual's innate baseline EEG power in both alpha and beta ranges was found to predict to some extent whether or not alpha and beta stimulation would produce enhanced or reduced alpha and beta power, and also, the duration of effect.

A Quantitative Electroencephalographic Study of Meditation and Binaural Beat Entrainment
Christina F. Lavallee, Stanley A. Koren, and Michael A. Persinger. The Journal of Alternative and Complementary Medicine. April 2011, 17(4): 351-355. doi:10.1089/acm.2009.0691.

The study objective was to determine the quantitative electroencephalographic correlates of meditation, as well as the effects of hindering (15 Hz) and facilitative (7 Hz) binaural beats on the meditative process.

Based on the results of this study, novice meditators were not able to maintain certain levels of θ power in the occipital regions when hindering binaural beats were presented, whereas when the facilitative binaural beats were presented, the experienced meditators displayed increased θ power in the left temporal lobe. These results suggest that the experienced meditators have developed techniques over the course of their meditation practice to counter hindering environmental stimuli, whereas the novice meditators have not yet developed those techniques.

The Clinical Use of Sound

Dr. Jeffrey Thompson is a pioneer in exploring the scientific basis of sound for health and healing. For more information, visit his website at The Center for Neuroacoustic Research.

Using Binaural Beats to Enhance Attention
Robert O. Sornson, Monroe Institute Research Journal, Fall, 1999

This study contributes to the growing body of evidence showing that specific brain-wave states can be enhanced by listening to audiotapes embedded with tones that produce frequency-specific binaural beating.

Binaural Auditory Beats Affect Vigilance Performance and Mood
James D Lane, Stefan J Kasian, Justine E Owens, Gail R Marsh, Elsevier Science Inc, 1998

Anecdotal reports suggest that binaural auditory beats within the electroencephalograph frequency range can entrain EEG activity and may affect states of consciousness, although few scientific studies have been published.... Results [of this study] suggest that the presentation of binaural auditory beats can affect psychomotor performance and mood. This technology may have applications for the control of attention and arousal and the enhancement of human performance.

EEG and Subjective Correlates of Alpha-Frequency Binaural-Beat Stimulation Combined with Alpha Biofeedback
Dale Foster, Memphis State University, May 1990

The purpose of this study was to determine the effects of alpha-frequency binaural-beat stimulation combined with alpha biofeedback on alpha-frequency brain-wave production and subjective experience of mental and physical relaxation.... An interaction effect was found in which the group with both alpha binaural beats and alpha biofeedback produced more treatment alpha than the group with alpha biofeedback alone.

Additionally, 9 of the 15 subjects with both binaural beats and feedback reported being able to control alpha production via their focus on the alpha binaural beats. The data suggest the possibility that binaural beats can be used to evoke specific cortical potentials through a frequency-following response. Further investigation is warranted into the possibilities of using binaural beats alone and in conjunction with brain wave biofeedback to promote the self- regulation and management of consciousness.

A Biological Rationale for Musical Scales
Kamraan Z. Gill, Dale Purves, Center for Cognitive Neuroscience and Department of Neurobiology, Duke University, Durham, North Carolina

"There is a strong biological basis to the aesthetics of sound. Humans prefer tone combinations that are similar to those found in speech." (Dr. Dale Purves)

In this study, the intervals and harmonics series of musical scales are compared to the harmonics produced by spoken language. The study finds a strong correlation between the two, suggesting that the musical scales worldwide are a reflection of physical vocal characteristics.

Musical Intervals In Speech
Deborah Ross, Jonathan Choi, and Dale Purves, Center for Cognitive Neuroscience and Department of Neurobiology, Duke University, Durham, North Carolina

This study shows the relationship of our physical vocal cords to musical intervals. It states that throughout history and across cultures, humans have created music using pitch intervals that divide octaves into the 12 tones of the chromatic scale and that human preference for the intervals of the chromatic scale arises from the way our phsyical vocal cords produce speech.

Musical Roots May Lie In Human Voice
Peter Farley, New Scientist

Frequency peaks are caused when a sound wave from the vocal cords is shaped by resonances of the throat and oral cavity. The researchers say that, aside from animal calls, speech emanating from oscillations of the human vocal cords is virtually the only natural sound that we hear as tones.

This fact, combined with the new finding that preferred musical intervals are better predicted by the acoustic quirks of the human vocal tract than by mathematics, leads the scientists to argue that the structure of music is rooted in our long exposure to the human voice over evolutionary time.

Songs of Ourselves
Christine Kenneally, The Boston Globe, Nov 9, 2003

New research suggests that we like music that sounds just like us.

Musicologists have long emphasized that while each culture stamps a special identity onto its music, music itself has some universal qualities. For example, in virtually all cultures sound is divided into some or all of the 12 intervals that make up the chromatic scale -- that is, the scale represented by the keys on a piano…. Human musical preferences are fundamentally shaped not by elegant algorithms or ratios but by the messy sounds of real life, and of speech in particular.