Research on Effect of Sound

A Foundation for Research in the Effects of Sound on Brain and Body Functions.

Lee R. Bartel
University of Toronto


The ideas in this paper grew out of several experiences: (1) research I have been involved with for the past 7 years on the effect of music on the rehabilitation of attention in head-injured adolescents; (2) my research on the stress of music-making and on the effect of music on stress; (3) experience with alternative medicine; (4) training to be a Neurofeedback practitioner; and (5) development of the "Music for Your Health" series of recordings.

This paper identifies potential areas and topics for research in music by making connections between rather disparate areas of research and scientific knowledge. Emphasis is on clarifying the foundational principles involved. Specifically, the nature, type and function of body and brain rhythms is explained; the premise and potential of EEG-based neurofeedback is described; a principle of physics, entrainment, is clarified; music as music and music as sonic energy is discussed; and the potential for music and sound to interact with body and brain is examined. Existing research studies addressing any of these connections are reviewed. Finally, potential research directions and methodological considerations are discussed.

[NOTE: This paper is published as: Bartel, Lee. (1999). "A Foundation for Research in the Effects of Sound on Brain and Body Functions." Proceedings of the International Conference of the Research Alliance of Institutes of Music Education (RAIME), London, Ontario. September 21-24. p.p. 58-64]

A Foundation for Research in the Effects of Sound on Brain and Body Functions.


Motivations and ideas for research always connect to some previous encounters and engagements with problems or concepts. My interest in the effect of sound on brain and body may have some root in the "decade of the brain" and the controversy around the "Mozart effect" but primarily it grows out of five immediate experiences. The first is a project at the Bloorview MacMillan Centre in Toronto with which I was involved as a Supervisor of a Post-Doctoral Fellowship and as research team member since 1992. In this project we focused on the effect of music on the rehabilitation of attention in head injured adolescents (Jutai, Knox, Rumney, Gates, Wit, & Bartel, 1997). The second was research I did through the Centre for Health Promotion on the stress of music-making and on the effect of music on stress in a study of musicians in the 19 professional orchestras in Canada (Bartel & Thompson, 1995). The third experience is my personal battle with back pain and the dramatic relief I obtained from alternative medicine including energy or vibrational approaches. The fourth contributor to my interest in the effect of music on brain and the relationship of brain-wave pattern to body function has been my training in EEG Neurofeedback, seeing first hand the direct and immediate effect of "external" stimuli on brain-wave response. The fifth is my continuing involvement as designer of recordings in a series called "Music for Your Health" that employs brain-wave entrainment through sonic techniques.

In this paper I try to draw on these disparate but related areas of interest, research, and scientific knowledge to identify potential foci or topics for research in music by making connections among them. Most directly I will try to clarify the foundational principles involved. Specifically I will explore: (1) the nature, type, and function of body and brain rhythms; (2) the premise and potential of EEG-based neurofeedback; (3) a principle of physics, entrainment; (4) the difference between music as music and music as sonic energy; and (5) the potential for music and sound to interact with body and brain.


Our Body's Rhythms. One of the most evident features of the body is its rhythmicity. We associate life itself with the beating heart. It is both our symbol and actual monitor of life. The breath is rhythmic although more directly under our control but no less related to life. There are many other rhythmic dimensions to the body. Organs and glands like the pituitary, pineal, and hypothalamus all pulse rhythmically. The craniosacral pulse is almost imperceptible but very steadily rhythmical. The function of the baroreceptor feedback loop is not perceptible at all to our senses but connects heart and brainstem in its 10 second pulse. Brain-waves are another rhythmic phenomenon observable from very slow pulsations of one every 10 seconds to very rapid of more than 60 pulsations per second. And, of course we are composed of molecules and atoms all in a constant state of orbiting vibration. In addition to this micro-rhythmic level, we all function with macro rhythms like the sleep-wake cycle and menstrual cycle.

The connection and relationship between the mechanical and biological, the electrical and chemical, the body and the mind, or physical matter and energy is not fully understood and many aspects are still unexplored. For example, what comes first, chemical process condition or substantive thought? Does volitional cognition drive brain-wave activity and brain state or do brain-waves allow cognition? How does the rhythmic function of one aspect of the body affect another? What is the interaction of one body's rhythmic patterns with that of another? What is the influence of the micro and macro rhythms of our universe on our thought and function - from sun spot cycles to the vibration of the earth's magnetic fields to the lunar cycle to the endless motion of the ocean waves to the vibrational frequencies in music?

Paradigm shift. The discovery and exploration of these micro and macro rhythmic phenomena in the human body and in the physical universe as a whole has begun a very slow paradigmatic shift. The nature and relationships of matter were the primary focus of Newtonian physics and its contribution to knowledge is undeniably important and extensive. However, the most significant changes in understanding in physics have come with Einsteinian theories of energy and its role in matter. But, only some of Einstein's theories have yet been explored and applied. Quantum physics is making progress and recently physicists demonstrated the possibility for an atom to physically exist in two places at the same time. In medicine the shift from an exclusively Newtonian mechanical and chemical basis of the body to a greater place for the Einsteinian energy and vibrational nature of the person is slow but underway. As this paradigm shift takes place, I believe we will see new understandings of the function of music and the role of the mind and brain-wave regulation.

Brain Waves and Mind States. A brief explanation of brain-wave states is important to understand the potential for neurofeedback and entrainment. The first level of brain-wave activity recorded with scientific equipment was in the 7-12 Hz band and so was named "alpha." It is the state associated with relaxation and the goal of traditional bio-feedback. The visual cortex quickly settles into this state when the eyes are closed. "Beta" is the state associated with alert problem-solving mental function. It has been further define in recent years as Sensory Motor Response (SMR) at 12 - 15 Hz, Mid-Beta at 15 - 18 Hz, and High Beta at 18-35 Hz. SMR is the state the sensory motor cortex seems to produces with muscular inactivity. High Beta is the brain state of anxiety and stress (hence the description of medication like propranalol as "beta-blockers" since they inhibit rapid brain-wave activity and thereby anxious thoughts). "Gamma" is the brain activity registered above the 35 Hz level and is not well understood. "Theta" (4 - 7 Hz) is a slow brain-wave activity band associated with meditation and trance-like states and deeply relaxed almost asleep states. All levels of brain-wave activity are produced constantly, but one band-width becomes dominant during the associated metal state. The ratio between theta and beta activity is often observed to be irregular in attention deficit cases with too little beta for the amount of theta. "Delta" (.1 - 4) is the brain-wave level associated with non-REM sleep.


EEG Neurofeedback is a technique for achieving voluntary control of brainwave activity. Typically one or two sensors are placed on the scalp to allow a computer to monitor brainwaves within one particular or a set of band widths. The trainee is required to produce beneficial brainwaves voluntarily with coaching from a second computer by means of game-like images and sounds (e.g., the Pacman moves forward when brain-wave activity is strong within the selected level). The clinician determines the level of brain-waves to be "practised" that will be most beneficial and in what part of the brain. This may change over course of treatment for some complex disorders. Typical disorders respond to 20 to 40 half-hour training sessions.

Neurologist Barry Sterman conducted extensive research in the late 1960's and laid the foundation for the use of brain-wave based feedback to address medical conditions. Other researchers include Lubar, Peniston, and Othmer.

The premise of "training" specific EEG levels is that brain state is self-regulated. Sterman obtained specific brain level control in operant conditioning cats. We are not conscious of this self-regulation but we do it largely by seeking a desired mental state, However, we may have difficulty attaining or maintaining a particular state (e.g., we may need a stimulant in the morning to attain a functional beta state.) Certain physical and mental disorders have been found related to brain-wave disregulation. For example, chronic left brain under-arousal seems related to Attention Deficit Disorders and to feelings like worry. Chronic right brain over-arousal along with left under arousal is related to ADHD. Brain-wave level instabilities are associated with other disorders like epilepsy, migraine, and fibromyalgia. In some cases it seems like the bran-wave level is "stuck" so treatment focuses on "dislodging" or disentrainment of the brain activity. Alpha-Theta level feedback is being used to focus on the lower level (thalamus) of the brain and tends to bring out deep memories and possibly traumatic experiences. Consequently, this type of brain-wave feedback is used in psychotherapy and is now found to be an effective treatment for addictions - especially alcoholism (Peniston & Kulkosky, 1989).

The practice of modern bio-mechanical medicine is dominantly "chemical" -- the patient suffering from ADD is given a chemical stimulant to effect a change in electrical brain activity. An alternative energy-oriented approach is "electrical" -- the brain is taught how to "unstick" its brain-wave activity and to effect the change desired. The premise and observed potential of EEG feedback is the assumption that the brain wants to function at optimum levels (it is easier and more satisfying to do what it is supposed to do when it is at the right "speed"). Once the brain-wave level becomes easily obtainable it will continue to function there. Therefore, by training specific brain-wave frequencies at the appropriate part of the brain, many ailments can be alleviated.


Entrainment is a phenomenon of nature that results in the synchronization of the rhythms or motions of separate entities. Christian Huygens, in 1665 "discovered" the phenomenon that clocks with the same pendulums can be started at various times but within a day will be swing together. Radio frequencies "lock" together when you tune your radio. Even in nature entrainment is evident. I grew up on a honey bee farm and noticed frequently that crickets in the honey shed chirped at the same speed as the squeaks from drive belts on the machines.

Pioneer research on the entrainment effects of sound was done in the 1970's. Researchers like Harrer & Harrer (1977), Landreth (1974), and others found that breath and heart rates readily synchronize to the rhythm of music. Robert Monroe and Gerald Oster examined sound processing in the brain and found that brain waves respond to music pulses. More recent research (Clynes and Walker, 1982; Foster, 1990) has focused on more specific aspects of entrainment effects and on other body rhythms and cycles.
It is evident that brain wave activity can be influenced by creating a regular brain impulse through light or sound stimulation. The frequency of brain waves follows or entrains to the impulse sent by the ear to the brain while "hearing" a regular musical pulse. Clearly the Hz levels desired for normal brain function cannot be created by actual pitches since any sound below 20 Hz is essentially inaudible and below 16 Hz breaks up into individual air waves. The ear could be presented with a regular pulse at 10 Hz for example by hitting a drum 10 times a second. The effect, however, would be far from relaxing. At the slowest brain-wave levels it is possible. There are other ways to send this signal to the brain.

A particularly effective way to do this is to create the pulsation inside the brain rather than at the hearing level. This is done by creating "binaural beats" - interference waves that result from presenting each ear with a pitch slightly out of tune with each other. The existence of the binaural beat effect was discovered by H.W. Dove, a German experimenter in 1839. His interest was the ability to identify direction of sound. The actual process involves the Olivary nuclei in each hemisphere of the brain. As the two processors respond to the electrical impulses from the ears, peaks are created when they fire simultaneously. These "pulses" radiate to the cortex as "a frequency following response" thereby entraining brain waves to the subtractive beat or pulse.
Because the sound processing systems in each side of the brain are involved, there is also a balancing of wave activity in the two hemispheres of the brain (Foster, 1990).


To understand the implication of what I have discussed regarding the nature of the body as vibrational and rhythmic, the importance of brain-state on mental function, the existence of entrainment as a reality of physics, and the possibility for sound to act as an entrainment generator, I must make one more important distinction regarding music and sound. Music is sound that we hear "as" music -it is constructed by our minds and, therefore, has cultural meaning and associations in general (style, mood), expectations, and related behaviours. Music also has specific referential connections. Music is also simply sound - acoustical raw material - noise - vibration. As sound it has sonic effects. It can be a stressor on the body causing sympathetic nervous system changes.

There are also sonic dimensions to "music" that we may not be aware of but that have direct effect on us vibrationally through entrainment or through process of which we are not yet aware. We often talk about music as if it were the notes that can be written down ignoring subtle differences in timbre, in vibrato, in tuning beating effects, or harmonic spectrum. Each of these has a vibrational characteristic that can well have significant effect on out mind and body. In addition we probably have physiologic acoustical imprints from mother's heart beat or other prenatal sounds. We have strong isomorphic associations like fast heart rate or running connected with a quick beat in music. We must recognize that "music" is only one part of the audio spectrum which in turn is only a part of the full vibrational spectrum (e.g., earth's magnetic field vibrates at 7.83 Hz); typical ocean waves have a peak wave every 10 or 11 seconds like the baroreceptor feedback loop).


There is currently a fascination among advocates for music education, parents of young children, and individuals wishing to "improve" the intellectual capital in our societies with the notion that "music makes you smarter." Interesting research has been done which sometimes shows remarkable results but then cannot be replicated. Part of the problem in the research associated with this idea is a confusion of music and sound. In no research I have seen have researchers shown any awareness of the sonic variables. That is not to say these studies have not found exciting results. However, it may not be the "music" that creates the effect.

There is clearly potential for sound to interact with the body and brain. The fact that brain-waves can be entrained with sound has huge potential for specific effects. These effects are most obvious in inducing state change. If one segment of the brain-wave spectrum can be boosted with sonic techniques to make it dominant while at the same time "suggesting" that state through the culturally associated music, then music can be created that will have powerful effects in reducing stress, focusing attention, inducing sleep, etc.

There is also evidence in research that processing sound as music "lights up" areas in the brain that function in other ways. It is probably the "warming up" of the neuronal networks that makes learning in those same spots easier. This was the basis for the research on attention I did with Jutai et al.

Most exciting is the possibility of accomplishing with sound some of the same effects as neurofeedback or combining EEG neurofeedback with sonic therapy of some type. Only a few studies to date have focused on this combination (Foster, 1990; Guilfoyle and Carbonne, 1997; Kennerly, 1997; Sanders & Waldkoetter, 1997). Research is showing that EEG neurofeedback can have a positive effect on specific health and educational problems (e.g., attention, epilepsy, panic attacks, migraine headaches, chronic pain, tinnitus, tics, Tourettes, etc.). If neurofeedback can address these problems, can music and sound? Could music work in conjunction with neurofeedback?

The possibility for music and sound to interact with body and brain has been demonstrated in research. The potential of that possibility, however, has not yet been established or explored in any detail. What is needed is specific research to examine the potential of sound to reinforce or replicate EEG neurofeedback treatments. As well, possibilities for sonic techniques to influence learning and cognition need to be studied. The use of EEG as a "window on the brain" also has considerable unrealized potential. The attention to sonic variables in music research is especially needed. We must recognize that music is vibration and must study it within the new paradigm of the body and mind as vibration and energy.

A Brief List of Relevant References


Achermann, P., and Borbely, A.A., (1997). Coherence spectra of all-night sleep EEG. Sleep Research, 26, 1.

Andreassi, J.L., (1994, second edition). Psychophysiology: Human Behavior and Physiological Response. Hillsdale, NJ: Lawrence Erlbaum Associates.

Bartel, Lee R. & Thompson, Edward G. (1995). Coping with Performance Stress: A Study of Professional Orchestral Musicians in Canada. The Quarterly Journal of Music Teaching and Learning. 5(4) pp. 66-74.

Gerber, Richard. (1996). Vibrational Medicine. Santa Fe, New Mexico: Bear & Company.

Sterman, B.M., Abarbanel, A., Kaiser, D.A., and Othmer, S. (1998). Neurophysiology Mechanisms of EEG Biofeedback. Training Manual Volume 5. Encino, California: EEG Spectrum.

Werth, E., Achermann, P., and Borbely, A.A., (1996). Brain topography of the human sleep EEG: Antero-posterior shifts of spectral power. Neuroreport. 8. pp. 123-127.


Arabanal, A. (1995). Gates, states, rhythms, and resonances: The scientific basis for neurofeedback training. Journal of Neurotherapy, 1. 15-38.

Cooper, R., Osselton, J.W., and Shaw, J.C. (1980). EEG Technology. London: Butterworths.

Othmer, S., Othmer, S.F., and Marks, C. (1992). EEG biofeedback training for attention deficit disorder, specific learning disabilities, and associated conduct problems. California Biofeedback (Fall), and

Peniston, E.G. and Kulkosky, P.J. (1989). Alpha-theta brain-wave training and beta-endorphin levels in alcoholics. Alcoholism, 13. pp. 271-279.


Atwater, F. H. (1997). The Hemi-sync process. WWW.monroeinstitute. org/research.

Goldman, Jonathan S. (1991). Sonic Entrainment. In Music physician for times to come. (edit. Don Campbell). Wheaton Ill: Quest Books.

McCraty, R. (1996). Entrainment. IHM Research Update, 2(1). p. 2

McCraty, R., Tiller, W.A., and Atkinson, M. (1996). Entrainment: A preliminary survey.

Oster, Gerald. (1973). Auditory beats in the brain. Scientific American, October.


Beaulieu, John. (1987). Music and sound in the healing arts. New York: Station Hill Press.

Clynes, M., and Walker, J., (1982). Neurobiologic functions of rhythm, time, and pulse in music. In M. Clynes (Ed), Music, mind, and brain: The neuropsychology of music. New York: Plenum Press. pp 171-216.

Jourdain, Robert, (1998). Music, the Brain, and Ecstasy. Avon Books Inc. N.Y: New York.


Foster, D. S., (1990). EEG and subjective correlates of alpha-frequency binaural-beat stimulation combined with alpha biofeedback.

Guilfoyle, G. and Carbonne, D. (1997) The facilitation of attention utilizing therapeutic sounds.

Harrer & Harrer (1977). Music, emotion and autonomic function, in M. Critchly and R. Henson (Eds), Music and the brain. London: Wm Heinemann.

Jutai, J., Knox, R., Rumney, P., Gates, R., Wit. V., and Bartel, Lee. (1997). Musical training methods to improve recovery of attention and memory following head injury. Paper presented at the Executive Function and Developmental Psychopathology: Theory and Applications Conference, University of Toronto.

Kennerley, R.C., (1997). An empirical investigation into the effects of Beta frequency binaural-beat audio signals on four measures of human memory. /research.

Landreth J.E. & Landreth H.F. (1974). Effects of music on physiological response, Journal of Research in Music Education, 22(1) pp. 4-12.

Petsche, H., Richter, P., and Filz, O. (1995). EEG in music psychological studies. In Music and the mind machine edited by R. Steinberg. Berlin: Springer-Verlag.

Sanders, G. O., and Waldkoetter, R.O. (1997). A study of cognitive substance abuse treatment with and without auditory guidance.