The Science of Sound
WHAT IS SOUND?
Sound is an expression of vibration that needs a medium such as air or water to exist. Sound is produced when something vibrates. For example, if we pluck a guitar string, the movement of the string compresses air particles in the direction of movement and leaves an empty vacuum of space behind it. Sound is created by air particles collapsing into the vacuum.
We produce sound in a similar way through vibrating our vocal chords with the airflow of our exhalation. The moment we produce a sound, a vibrational energy moves through the molecules of air at a speed of approximately 742.5 mph to reach our ears. Sound travels over four times faster in water because the particles are much closer together so the vibration energy can be quickly transmitted from one particle to the next.
How sound moves through mediums is just the tip of the iceberg. To deeply understand how sound works in healing, we will focus on sound’s three major characteristics: form, frequency and amplitude.
The form of a sound is what gives the sound its “Timbre” or Tone. What produces the sound determines the tone. For example, the sound form produced by a human voice has a different tone than a guitar. While an instrument or voice can sound different based on its shape and build, the sound emitted from the source is always spherical. Sound is round. The vibrational energy of sound does not move in a straight line but expands in all directions in a series of spherical wavefronts from the source.
Acoustic engineer John Stuart Reed has shown how we can ‘see’ sound emissions as rapidly expanding spheres or bubbles as seen in the diagram below. His research shows a more correct way of understanding sound as opposed to the widely-held theory that sound is a pressure wave. This theory assumes air particles are moving back and forth, propagating 2-dimensional “waves” of sound. Though back-and forth motion (oscillation) is a natural phenomena, it does not describe the movement of sound through air. It is true that a sound vibration causes compression (moving air molecules close together) and rarefaction (air molecules moving away from neighbors to create a vacuum) but this does not prove that sound travels in a longitudinal wave.
Instead, it seems that sound travels through air molecules as a 3-D helical ‘wave’ because the air molecules themselves have a spiral movement. This theory accords with the movement of planets, electrons and other vibrating bodies which rotate around a center rather than creating pressure by moving back and forth. This new understanding of sound moving in a dynamic helical motion as opposed to a linear motion is extremely relevant to sound healing. The helical motion of the sound has a vortexing effect that makes sound an ideal medium for transmitting healing harmonic energies deep into the body.
Cymatics is the study of vibrational waveforms that was first developed by Dr. Hans Jenny. It is derived from the Greek “kyma” meaning wave and “ta kymatica” meaning “matters pertaining to waves.” The cymascope is a scientific instrument that makes visible the inherent geometries within sound and music. The cymatic images below are known as cymaglyphs and were produced by a cymascope.
The diagram below shows a cymatic image of a sonic bubble cut in half to reveal its internal structure and a 2D cymatic slice through the bubble.
The cymatic images of Clair De Lune (meaning “Moonlight” in French) show the rich harmonic geometry of this soulful song.
This cymatic image captures a ‘frozen’ moment of sound produced by a violin. While the cymatic image of a violin’s sound captures its rich harmonic structure, cymatic images of noise reveals a disharmonic structure. Since sound itself remains invisible to us, it important to keep in mind that the sounds we make and expose ourselves to affects the harmonic structure of our being. It is not hard to imagine that violin music has a soothing effect on the body while the disharmonic noise of a truck engine has a stressful effect on the body. In part, it is the form of the sound that makes the difference between whether a sound harms or heals!
We can think of frequency in terms of how “frequent” an event occurs. With regard to sound, frequency is the number of vibrations occurring per unit time. The standard unit for measuring sound frequency is the Hertz. 1 hertz = 1 cycle/second. For example, if I pluck a string that is tuned to the ‘Middle C’ note of 256hz, the whole string appears to vibrate 256 times per second. The Hertz of a sound is how many times a sound repeats –or cycles through- itself per second. We can see this same concept in Astrophysics since the Earth makes one cycle around the sun per year similar to how a Middle C’ note cycle 256 times per second! Whether it’s the number of vibrations per second, or the number of orbits of a planet per year, a periodic motion is practically always circular because it represents the time it takes to complete one cycle before repeating itself.
Another property of frequency is that low frequencies correspond to low pitches while high frequencies correspond to high pitches. For example, a man with a deep baritone voice has a low frequency and pitch while a female soprano’s voice has a very high frequency and pitch. The 2D waves in the diagram below are useful in demonstrating the difference between high and low frequencies but lets not forget that sound is actually a 3D Helical wave that expands spherically!
This instrument above is called a monochord. It has a string fixed at both ends and stretched over a sound box. The monochord can be used to demonstrate the mathematical ratios of the frequencies it produces by manipulating its moveable bridge (the “dark triangle” in the diagram). If we plucked the open string on the monochord, we would hear its fundamental note of 100hz, or 100 cycles per second. By moving the bridge to the center, we divide the string in half so that each segment now vibrates at 200 cycles per second when plucked. The vibration cycles twice as fast through each string because it only has half the space to vibrate! This doubling the frequency of the fundamental is called going up an octave.
Going up an octave creates a 2:1 ratio which means one half of the string has twice the vibration as the open string. Any two notes that are one octave apart have a 2:1 ratio. The Monochord can produce different ratios such as 3:2 ratio (a Perfect Fifth) or a 5:4 ratio (a Major 3rd). In music, the term ‘intervals’ is used to describe these ratios. An interval is the space between two pitches (notes). For example the distance between the C and G note is the interval known as the Perfect Fifth (3:2 ratio). How we hear a pitch is subjective and based on our perception of the sound, yet our ears can distinguish certain pitches such as the Perfect Fifth more than others because of its stable pleasant sound.
Here is a fun video to learn the sounds of the intervals:
There are many musical systems that space out the notes/pitches of an octave differently (which creates different harmonic ratios between the intervals). For example, the heptatonic “Western” scale consists of seven notes -C-D-E-F-G-A-B- per octave, (before resolving to the “C” note of the next octave) while most Chinese music consists of a five note pentatonic scale.
The tuning system also changes the pitch of the notes. Both an Equal Temperament tuning or a pythagorean tuning system could both be used in the seven-note “Western” scale. Equal Temperament would tune the “A” note to 440hz while Pythagorean Tuning would tune the “A” note to 432hz. Different tuning systems are based on different harmonic ratios between the intervals. In Equal Temperament, the frequency interval between every pair of notes that are next to each other has the same ratio so we perceive an equal “distance” from every note to its nearest neighbor. But in Pythagorean tuning, the frequency ratios of the intervals are all based on the 3:2 ratio of the Perfect Fifth.
In sound healing, it is preferable to use the pythagorean tuning system because its harmonic ratios greatly correspond with the proportions found in the natural world and human body. There is much more to say on this subject but for now it is enough to know that music tuned to 432hz is much better for us than the current 440hz tuning standard which is present in virtually all the music we hear today! You can find great 432hz tuned music and healing tones on youtube!
These cymatic images show us that 432hz has a much more coherent and harmonic form than 440hz!
Another important aspect of frequency is that it determines IF and HOW a sound is heard. For example, the human range of hearing is between approximately 20 and 20,000 Hz (cycles per second), whereas the cells of the body communicate in the 10- 180 nm range. Despite communicating in different ranges, it is possible for us to communicate with cells through the sound of our voice! I studied with renowned sound healer Fabien Maman who used a kirlian camera to document the effect of sound frequencies produced by the voice and instruments on the electromagnetic energy fields of healthy human cells. He discovered that the color and shape of each cell’s energy field changed according to the pitch and timbre of each musical note.
The first photo shows a healthy cell lighting up with increased vitality after hearing the fundamental note it resonates with. The group of photos shows various cells responding to the chromatic scale as played by a xylophone. The last two photos shows a healthy hemoglobin (a protein in red blood cells) with no sound and then with sound produced by a tuning fork. Maman not only discovered sounds that energized the body, he also found dissonant sounds that neutralized harmful cells to return the body to a state of health!
The last aspect of frequency we’ll focus on is that frequency is a carrier wave for information. If you change the FM station on your car radio to a new station, you have changed the frequency and are now listening to different information in the form of another song! This quality of frequency is extremely important for sound healing because it shows how frequency acts as the vehicle to transmit healing frequencies to our body, mind and spirit.
Amplitude is the size of a vibration over time in a given space. The amplitude determines a vibration’s volume which is measured in decibels. The simple diagram below demonstrates that the intensity -or magnitude- of a vibration is bigger when the amplitude is higher.
For example, we can increase the amplitude of a song to produce a louder sound and greater vibration by turning up the volume on a stereo. These “higher” amplitude waves have more energy than smaller waves at a lower volume. But it does take more electrical energy to maintain the sound at a higher amplitude. This example shows us that a higher amplitude contains more energy. The energy content of a song’s amplitude is not only determined by the volume we are listening to it at but also the intensity of the song itself. For example, Queen’s “We Will Rock You” has more energy and packs more power than Brahm’s “Lullaby”! The energy of the amplitude is a key aspect of sound healing because it determines the feeling of the healing and its overall effectiveness.
Music vibrating paint on a speaker demonstrates how increasing the stereo’s volume increases the sound’s intensity!
The Inverse Square Law of Sound shows that a sound becomes less intense the further away it is from its source.
We can think of frequency as ‘how close’ the sound waves are to each other while the amplitude envelope is the ‘height’ of each wave determined by the change of its volume and intensity over time. This diagram below of electrical energy is also applicable to understanding sound because it shows the relation between 1hz, the frequency one cycle per second and its corresponding amplitude. This diagram also shows the phase of different waves. Since the two waves began at different times they are considered ‘out of phase’ but they would be ‘in phase’ if they started at the same time. Phasing is important in sound healing because the healer’s sound gets ‘in phase’ with the rhythm of a person’s energies to bring them back to their natural frequencies of health and harmony.
Frequency is just the carrier wave of the signal/information. It is the amplitude envelope (the changes in the amplitude of a sound over time) that contains all the information and emotional content riding on the wave. For example, a dog can tell whether it’s being praised -“Good dog!”- or scolded -“Bad dog!”- by the inflection of their owner’s voice. It’s the rise and fall of the voice over time that is communicating the meaning behind the words. Therefore, the amplitude envelope shows us it’s not so much about what we say and more about how we say it!
The images below are photographs of water crystals taken by Japanese researcher Masaru Emoto. He demonstrated how the conscious intention in thoughts, words, visualizations and prayers has the power to bring harmony to the structure of water. His amazing discovery shows us that we can use power of conscious intention to resonate our body -which is mostly composed of water- with states of peace, joy and vitality. His research is extremely relevant to sound healing since the energy of the conscious intent is the amplitude envelope that rides on the frequency. But sound is not just a delivery method for healing energy. The pure harmonics of sound also structure and amplify the energy of the conscious intent to bring the body, mind and spirit back into harmony!
Maseru’s photos can help us visual the emotional content (amplitude envelope) of cymatic images produced on a cymascope. For example, consider the difference between a cymatic image of a man saying “I love you” to his wife with an insincere-sounding voice and a cymatic image of him saying “I love you” with a warm heartfelt voice. Because the carrier wave (frequency) of the man’s overall voice is similar in each case, the cymatic images would all have a similar shape in general.
However, when we compare the inner structure of images, there would be a difference because the emotional content (amplitude envelope) of each is very different!
The energy of the ‘Heartfelt I love you’ would create a very defined geometrical and symmetrical image while the energy of the ‘insincere I Love you’ would show a less symmetrical and defined image. This example shows us that the emotional content deeply affects how harmonic a sound’s energy will be. In sound healing, the emotional content is key because the healing energy is in the harmonic structure of the sound itself!
The changes in the amplitude envelope are known as the attack, sustain, release, and decay of the signal. These changes describe the way in which the intensity or volume of the signal can rise and fall over time. We can think of each change, or modulation, as an ‘essentic form’ that carries a specific emotional content. Scientist Manfred Clynes created the science of Sentics which is the study of waveforms of touch, music and emotion. He developed the technology to show how emotions such as ‘joy’ and ‘anger’ have distinctly different ‘essentic’ forms.
Clynes proved that people create the same essentic form for an emotion regardless of gender, race, culture or upbringing.
The diagram above shows essentic forms produced on a sentograph, a finger-pressure sensor that recorded subjects response to video and images that induced certain emotional states. States of pleasure caused the finger to lift and pull toward whereas states of pain or dislike caused the finger to push down and away. The upper trace shows vertical finger pressure while the lower trace shows horizontal finger pressure. Each trace represents the average of 50 expressions recorded by Clynes in 1969.
The diagram below shows changes in respiration and heart rate during a sentic cycle. While respiration accelerates during hate and anger, it slows during love and speeds up for sex.
Clynes also created a healing program where people experienced a sentic cycle of emotions: no-emotion, anger, hate, grief, love, sexual desire, joy, and reverence. Thousands of people have benefited from this program by becoming more calm, alleviating depression and overcoming addictions. In sound healing, the emotional content produced by the movement of the voice and instruments is similar to the sentic cycle. The sound dredges up the suppressed emotions to be fully expressed and integrated and then transitions people to feeling the peak emotions that they desire to resonate with on a daily basis.
The scientific foundation of sound healing is clearly demonstrated in the the interrelationships between form, frequency, and amplitude. While understanding sound through the lens of science is deeply informative, the true magic of sound is known in our felt experience of it. By simply being present and abiding in the vibration of the universal sound current, we are given access to the power of sound on a whole other level. Some of the greatest sound healers know nothing of the science of sound yet their healing powers are incredible because of their intuition and spiritual connection to the sound current. At the end of the day, it is both our scientific knowledge and spiritual knowing of sound that enables us to use sound to heal and co-create a beautiful world together!