The Power of Voice in Healing Emotions and Psychological Wellbeing: An Unveiling of Science

From the comforting lullaby of a mother to her baby, to the soothing cadence of a therapist during a counseling session, the human voice possesses a profound power that can deeply influence our emotions and psychological states. In this article, we will explore the scientific basis for this fascinating phenomenon, with a particular focus on how the voice can play a role in healing emotions and mitigating psychological distress.

Harnessing the Power of the Human Voice

A Vital Tool for Emotional Expression

In communicating emotions, words constitute only a fraction of the message. Non-verbal elements such as tone, pace, volume, pitch, and rhythm of our voice can convey a vast range of emotions – joy, anger, fear, sadness, surprise, disgust, and more. The emotional subtleties embedded within vocal cues provide a unique pathway for emotional healing and therapeutic interactions.

The Science Behind the Sound: Vocal Frequencies and Healing

Recent research has begun to uncover the underlying mechanisms behind the healing potential of the voice. It has been found that certain vocal frequencies can induce a physiological response in the listener. The process is akin to “auditory-driven emotion synchronization”, where the listener’s emotional state aligns with the emotional content of the voice they are hearing.

It’s not just the emotional content, but also the physical properties of sound waves produced by human voice that can have a healing effect. Resonance, for instance, is an important aspect. Certain sound frequencies can cause different parts of the human body to vibrate sympathetically, which has been linked to various health benefits such as stress reduction and improved mental clarity.

The Voice and The Mind-Body Connection

The Voice as a Means to Release Emotional Energy

Scientific studies suggest that using one’s voice can have therapeutic effects on the mind and body. For example, a technique called “toning” involves creating prolonged vocal sounds, which can help release pent-up emotions. Similarly, singing has been associated with decreased anxiety and increased feelings of wellbeing.

Biofeedback Mechanisms

Moreover, biofeedback mechanisms appear to be at work during vocalizations. This involves creating sounds and then consciously modifying them based on feedback from one’s body. The voice can thus become a tool for self-regulation, helping to calm the nervous system and promote emotional healing.

The Power of the Voice in Therapy and Counseling

Vocal Psychotherapy

In the realm of therapy and counseling, the power of voice is being harnessed through methods like Vocal Psychotherapy. It uses the voice, including singing and vocal improvisation, to tap into non-verbal and unconscious emotional material, creating a powerful means of expressing and processing deep emotions.

Sound and Music Therapy

Sound and music therapy, which often incorporate the human voice, have also shown significant promise in improving mental health. This includes reduction in symptoms of depression, anxiety, PTSD, and even physiological changes like lower blood pressure and heart rate.

Empathy and Connection: Healing through Others’ Voices

The healing power of the voice is not just about self-expression. The voices of others can also have a profound effect. Empathetic and supportive verbal communication from others, whether it be from a friend, a family member, or a therapist, can significantly aid emotional healing. This reflects our innate human need for connection, empathy, and understanding.

Science is beginning to unveil the extraordinary power of the human voice in healing emotions and mitigating psychological distress. It’s evident that the voice can be an effective tool in emotional expression, self-regulation, and therapeutic interventions. As our understanding of this fascinating subject deepens, it may open up new avenues for enhancing mental health and wellbeing through the transformative power of voice.

Sound Healing and your voice

Laur Fugere, an expert in the field of sound healing and vocal development, has designed this unique sound healing certification course to empower individuals to explore their voice’s innate healing capacities. Leveraging years of professional experience and extensive knowledge, Laur guides you through a journey of self-discovery, where your voice becomes your healer.

7 Benefits of Sound Therapy and Sound Baths

Far from being merely a New Age trend, sound healing and sound therapy have been used for thousands of years to heal and strengthen the body and mind by restoring balance to the body’s vibrational frequencies, calming the mind and clearing negative emotions, boosting the immune system and improving cellular health.

Sound therapy and sound baths are an intuitive practice wherein the therapist or practitioner uses various instruments including tuning forks, gongs, tibetan bowls, crystal bowls, drums, tingshas, shakers, chimes, harps, didgeridoo and also the human voice to produce specific sounds, frequencies, vibrations and harmonics to promote healing of the mind and body.

A steadily growing body of research and studies is confirming the effects of sound on the mind and body. Noise, or negative sounds have been shown to have a detrimental effect, whereas positive, coherent or harmonic sounds have been shown to provide many benefits.

Here are 7 benefits of sound healing and sound therapy: 

  1. Lower blood pressure

Tuning forks, for example, have been shown to release Nitric Oxide when used on the body. Nitric Oxide is a cellular signalling molecule and powerful vasodilator which is produced by almost every type of cell in the human body and is extremely important for blood vessel health. As a signalling molecule, it controls vascular tone and blood pressure. As a vasodilator, it relaxes the inner muscles of blood vessels, causing the vessels to widen, which consequently increases blood flow and lowers blood pressure.

The health effects of sound baths was studied and published in the American Journal for Health Promotion. Subjects listened to a Himalayan singing bowl or sat in silence for 12 minutes, both followed with 20 minutes of mediation. The study showed the group who listened to the Himalayan singing bowl experienced larger drops in blood pressure and heart rate.

  1. Improved sleep

Sound healing has been shown to help individuals fall asleep faster and to improve sleep quality overall. Certain sounds promote sleep by changing brainwaves to Delta waves, which are associated with deep sleep.

Generally, sound therapy and sound baths are highly effective at reducing stress and anxiety, which are common causes of insomnia, trouble falling and staying asleep. By calming the mind and reducing stress and anxiety, the mind can more easily fall into deep sleep, removing interruption to the essential restorative processes that take place while we are sleeping.

Many who have enjoyed sound therapy or sound baths regularly report they need less sleep than they previously required, with individuals reporting they needed one to three hours less per night.

  1. Pain relief

Studies of vibroacoustic sound therapy have shown improved pain management. Sound therapy stimulates brain circuits to relieve pain and enhance the areas of the brain involved in pain management. Vibroacoustic sound therapy uses audible sound vibrations that are applied to the body. Tools include singing bowls or crystal bowls placed on the body or electronic equipment, both of which will create a combination of tones and vibrations that resonate throughout the body and at the cellular level.

Experiencing binaural beats has also been shown to help with relieving aches and pains. Binaural beats work by providing one tone of a specific Hz in one ear and a different one in the other ear, which results in a new frequency, a third tone, which is called a binaural beat. The brain responds to this frequency by aligning the brainwaves to this frequency.

  1. Increased energy and confidence

Daily stress, anxiety, pressure or even noise pollution rapidly depletes our mental energy and consequently our sense of well-being and confidence. By using sound and vibration to move the mind into a calm state, the brain has an opportunity to recharge its energy reserves and participants of sound therapy or sound baths report feeling highly refreshed and energised after completing a session. Regular participation can help maintain consistent mental energy by promoting overall brain health. 

Specific vibrations and frequencies can be used to align the brain with Beta frequency, which stimulates energy. 

  1. More focus

Our energy levels are closely related to our ability to focus and the degree of focus we are capable of. When we are in a fight or flight state, which is a common response to high levels of anxiety or stress, our sympathetic nervous system is switched on and triggers an involuntary bodily response to a stressful situation, flooding the body with stress hormones, increasing heart rate and sending blood to the muscles. As a result, our cognitive abilities including our abilities to focus are diminished. 

By promoting a state of mental calmness through exposure to sounds, vibrations, tones and frequencies, the body and mind can be calm and return to a state capable of focus. High levels of focus can be achieved through exposure to specific frequencies and vibrations. For instance, when experiencing Beta brainwaves, individuals have heightened analytical and problem solving skills and a greater ability to keep attention focused. 

  1. Lower stress levels

Meditation has been widely acclaimed throughout history for its stress reduction effects. However, many find meditation to be a daunting prospect as our modern minds are a struggle to clear and calm. Sound meditation has been shown to be an excellent alternative to traditional mediation as a way to lower stress levels. For instance, a 2019 study has shown Didgeridoo sound mediation is as effective as silent meditation for decreasing stress.

Exposure to gongs, tingshas, bowls (crystal, singing and Tibetan) for 60 minutes produces significant reduction of tension, anxiety and depression in participants, according to a 2016 study.

The detrimental effects of stress at the cellular level can be reduced or even eliminated by participating in sound therapy sessions or sound baths. Sound heals at the cellular level by sending vibrational frequencies into the body. This can be done by application of instruments such as tuning forks or vibroacoustics by creating and promoting a healthy cellular vibration which allows the cells to function optimally and to heal.

  1. Enhanced emotional regulation

By exposing the brain to certain sounds, vibrations and frequencies that promote calmness, reduce stress, increase energy and focus, the brain becomes holistically healthier. A healthy brain is essential for emotional regulation. 

The incredibly powerful spiritual effect of sound therapy and sound baths create and nourish a deeper connection to the higher Self and to the universe or one’s God. This, in turn, promotes a deeper sense of spiritual well being, purpose and meaning. This feedback loop fosters a greater ability to respond to our inner and outer life in an emotionally appropriate and regulated way. Last but not least, our capacity for compassion and love depend on this deeper spiritual connection that is experienced through sound, vibration and frequency.

Sound healing and sound therapy can be effectively used as a component in an integrative approach to healing and preventative health. These benefits can be equally derived and enjoyed from individual sound therapy sessions or sound baths or in a group setting. Forest or nature baths provide a wonderful means of accessing the healing sounds of the natural world. In addition to live sound baths, pre-recorded or digital sound baths are a convenient and easy way to access these benefits when you need them or as part of your daily health routine. 

A trained sound therapist will work with you to help you identify and discover sounds that you connect deepest with so that you can receive the greatest benefit from your sound therapy session or sound bath. To learn more about becoming a sound therapist see the sound-therapy-certification.

The growth of the sound therapy industry

sound therapy online course preview

Music is undergoing a sudden wellness transformation and Sound Therapy is what everyone is talking about.

More scientific studies on sound are gaining interest from mainstream medicine. The number of people that are reporting beneficial results after having had a sound therapy session continues to grow.  

Yoga teachers, massage therapists, Reiki practitioners, voice teachers, musicians, to name a few, and even psychologists have started to incorporate sound therapy into their sessions.

The fact is that music is undergoing a sudden wellness transformation, and sound therapy is the wellness trend everyone is talking about. 

You will find sound therapy videos with millions of views on Youtube and an ever expanding market for sound therapy products, from crystal bowls to tuning forks, gongs , bells and more.

It’s even becoming popular within the digital music space, Icelandic band Sigur Ros have started offering sound baths. Nigel Stanford is a New Zealand composer, his video called Cymatics features audio visualized by science experiments 

The success of studios around the world, like New York City’s Woom Center. Los Angeles, The Soundbath Center, and LA Sound Healing. And at wellness destinations like the Four Seasons Resort Orlando and Miraval in Tucson, all points to a growing demand for sound therapy in the wellness industry. 

Sound healing is at the forefront of the wellness industry. The Institute of Conscious Evolution works to educate people about the effects of sound on the body and mind.

It is through sound that we feel like we connect to something greater and share an experience with others. Sound can inspire us, help us escape and disconnect, motivate us, relax us and, most importantly, it can help heal us. There is no woo woo. This is because as your brain perceives sound and as your body perceives vibration, it can trigger different chemicals in your system. 

Our goal with this platform is to provide a more scientific approach to understanding sound therapy and how it works. We continue to collect and synthesize research on the subject of sound and how it affects us, with the intention of making sound therapy more accessible to a larger audience. IOCE sound therapy certification offers everything you need to know to get you ready to start your sound therapy journey.

A Study on 528 Hz Music vs 440 Hz

sound therapy certification tuning systems

Various effects have been ascribed to the solfeggio frequency, but is it real?

Music of frequency (528 Hz) has lately attracted attention as “healing” music. Usually, the reference tone for tuning is 440 Hz, and this is the international standard frequency (we refer to this as 440 Hz music). In this musical scale, there is no 528 Hz note. Music that is tuned and composed using a scale that includes 528 Hz is called solfeggio frequency music.

A recent study examined the effects of 528 Hz music on nine participants who listened to the music from a seated position beside a speaker. The music was soothing piano music, and the only difference between the two musical conditions was in frequency, which was either 528 Hz or 440 Hz.

The study reported that levels of oxytocin increased significantly more immediately after listening to 528 Hz music than after listening to 440 Hz music, where the levels of oxytocin also increased, but the difference was not significant.

After listening to 528 Hz music, the levels of salivary cortisol were significantly reduced 30 minutes later. In contrast, after listening to 440 Hz, levels of cortisol only slightly decreased after 30 minutes.

Based on salivary biomarkers, electrocardiogram, and a mood state questionnaire, the study found that stress levels were reduced following five minutes of exposure to 528 Hz music, whereas this was not the case for 440 Hz music.

Overall, they found that people who listened to 528 Hz music felt less stressed, but this could not be confirmed for 440 Hz music.

Although the sample size of this study was limited, these are interesting findings nevertheless.


Cymatics – Hans Jenny

sound therapy course hans jenny

The study of wave phenomena is also called ‘Cymatics’. The term was coined by Hans Jenny (19041972), a Swiss follower of the philosophical school known as anthroposophy. Anthroposophy is a philosophy formulated by Rudolf Steiner. It’s based on the premise that the human intellect has the ability to contact spiritual worlds.

It was formulated by Rudolf Steiner (q.v.), an Austrian philosopher, scientist, and artist, who postulated the existence of a spiritual world comprehensible to pure thought but fully accessible only to the faculties of knowledge latent in all humans.

Inspired by systems theory and the work of Ernst Chladni, Jenny delved deeply into the many types of periodic phenomena, especially the visual display of sound. He pioneered the use of laboratory-grown piezoelectric crystals, which were quite costly at that time. Hooking them up to amplifiers and frequency generators, the crystals functioned as transducers, converting the frequencies into vibrations that were strong enough to set the steel plates into resonance. He made the resultant nodal fields visible by spreading a fine powder of lycopodium spores from club moss, as well as many other methods and materials.

Jenny published two volumes entitled Kymatic (1967 and 1972), in which he repeated Chladni’s experiments. He claimed the existence of a subtle power based on the normal, symmetrical images made by sound waves. According to Jenny, these structures, reminiscent of the mandala and other forms recurring in nature, would be a manifestation of an invisible force field of the vibrational energy that generated them. In one of his experiments, he used a vocalization in ancient Sanskrit of Om (regarded by Hindus and Buddhists as the sound of creation) and the powder formed a circle with a centre point, which was one of the ways in which Om had been represented.

Sound Therapy, Music Therapy and History.

Sound Therapy, Music Therapy and History.

Sound therapy is not new. 

In the latter half of the 18th century, Diogel, a French physician working at Salpetriere Hospital in Paris, used to bring musicians to his ward for live music sessions. He would record changes in the blood pressure and pulse rate of the patients as the music played on. He found that music lowered BP and reduced heart rate—the findings suggested an enhancement in the working of the parasympathetic system. This was one of the earliest systematic investigations exploring the effects of sound, and music in particular, on human health. 

The phenomenon that music and sound can affect the general working of a human body, has been known since ancient times.

The great Greek philosopher Aristotle, for example, mentioned in his famous work, De Anima, that the sound of a flute leads to the arousal of strong emotions and purifies the soul. The ancient Egyptians, too, used music to heal the sick. The Greeks recognized the association between music and healing by designating a single god, Apollo, for both.

Throughout our thousands of years of cultural existence, sound has been a part of the healing process. Shamans around the world have used the repetitive beating of drums to transcend themselves and their patients to an altered state of consciousness, capable of imparting mental and physical wellbeing. The earliest undisputed records of shamanistic methods date back to thirty thousand years ago. For a long time in human history, the practice of medicine and healing was the domain of religious and spiritual authorities, and although it has been superseded by modern science, in one way or another, the tradition continues to this date. 

Vedic philosophers in ancient India used chants and monosyllabic words, called Mantra, to calm the senses and mind. The theme runs throughout the religious and spiritual world. 

From the Jewish Kabbalists to the Sufis and mystics of the Muslim world, sound and music have been an important part of not only achieving spiritual transcendence but also healing the mind and body. Physical healing in these practices, however, is often secondary—almost a byproduct—to the primary goal of achieving spiritual enlightenment and a sense of bliss. 

Pythagoras, the great Greek philosopher and mathematician, was probably the first one to adopt an organised approach to using sound as a healing apparatus, with what he called musical medicine. Working around 500 BCE, he and his disciples would use melodies composed to treat psychological conditions like depression, aggressive behavior, and anger.

The association of sound with modern medicine began two hundred years.

The association of sound with modern medicine began two hundred years ago when the stethoscope was invented. The French physician René Laennec used it for the first time to investigate the sounds generated by the heart and lungs and found the findings to compare favourably to observations made during autopsies. 

Listening to the heart and lungs via a stethoscope is now a vital step in the clinical examination of patients. In addition, the rumbling sound generated by the movement of our intestine and the gurgling sound of blood flowing through an artery narrowed by a clot or constriction, like the carotid or renal arteries, can be heard via a stethoscope to provide important diagnostic clues. 

The association of sound with medicine is old. The resurgence of musical therapy and the widening applications of audible and inaudible sound waves in modern medicine means that it is timeless too. Sound has turned out to be so much more than a method of communication. It has also turned out to be a vessel of health and disease.

Infrasonic Vibrations

infrasonic vibrations

Humans vocalize — they produce sound with their vocal cords. In addition, they produce sonic signals through their muscles and other organs whose frequency is lower than that audible by humans.

Raise your elbows and make a fist. Now place your thumbs in the openings of your ears to close the ear canals. Do you feel a rumbling sound like the rolling of thunder in the distance? If not, clench your fists tighter and listen carefully. This low hum is the sound produced by the contraction of your muscles. Your body produces sound waves with a frequency lower than the detection limit of our ears, that is, 20 Hz. They are known as infrasonic vibrations. Frequencies around this range are normally not audible but the vibration energy can be detected and felt. 

Infrasonic vibrations generated by muscles.

The origin of the infrasonic vibrations in humans has been attributed to physiological processes like heartbeats, blood flow, and rhythmic movements of respiration, among others. Though the field as a whole has been under-explored, the infrasonic vibrations generated by muscles are studied in relatively more detail. Beginning with the work of G. Oster and J. S. Jaffe in the 1950s, experiments using transistorized stethoscope have shown the effects of various factors on the sonic signals produced by muscles. Increasing the load on a set of muscles, the elbow or thigh muscles, for instance, lead to a higher intensity sound, as recorded by the microphone. Reducing blood supply to the muscles, by inflating a cuff over the elbow, had no significant effect on the tonal qualities of the sound, suggesting that the generation of the sonic signals is an intrinsic property of skeletal muscles, irrespective of its activity and blood supply.

The phenomenon that muscles produced infrasonic waves was first demonstrated by F. M Grimaldi in 1665. Later, Herroun and Yeo noted that electrical stimulation of muscles produces similar sound waves as those generated by voluntary movement.

The resonance frequencies generated by other individual organ systems have also been determined.

Muscle is not the only human organ that generates infrasonic vibrations. Human bodies are complex three-dimensional structures with millions of physically active microunits .

The amplitude of the vibratory waves is normally between 1 to 5 microns, though significant variations exist depending upon the state of body activity. The sonic waves produced by muscles have, predictably, a higher frequency than those produced by the rest of the body, reaching up to 30 Hz, barely touching the audible frequency range. The sound pressure, however, is too low — 6 to 7 db — to be audible without amplifying devices. 

The heart resonates at a frequency close to 1 Hz, while blood circulation generates a resonance frequency less than that. As a result of all its neuronal activity and changes in action potential, resonance activity of the human brain is estimated to be around 10 Hz.

A monotonous noisy note can alert to the possible development of a seizure

Scientists have been successful in transforming brain oscillations into audible sound. A special instrument, colloquially known as the brain stethoscope, consists of a band with a built-in speaker that converts the brain waves, otherwise recorded on an EEG strip, into sound waves. A monotonous noisy note can alert to the possible development of a seizure. This can be particularly helpful in the detection of what is known as silent seizures, which are devoid of the usual violent activity associated with fits.

Infrasonic signals are a well-known method of communication in the animal kingdom.

The functional implications of infrasonic vibrations in humans are less clear compared to other species in the animal world. Infrasonic signals are a well-known method of communication among a number of mammal and bird species. Pigeons, for example, can detect low-frequency sound waves and it is proposed that sensing these signals help them in homing, orientation, and migration. Pigeons and Guinea Fowl may also use these infrasonic signals to sense distant thunderstorms and subsequent rain. Among mammals, elephants and whales are known to produce and detect infrasonic signals. In the case of elephants, these low-frequency sound signals, commonly called rumble vocalization, are used over long distances for coordinating movement and spacing within a social group, to communicate with affiliated individuals, and to trigger defensive behavior. Whales use infrasonic signals to communicate over long distances, up to hundreds of miles.

Acoustic field around the body.

Taken as a whole, the infrasonic vibrations can be thought of as forming an acoustic field around the body. This is not the only energy field emitted by our bodies. It has been known that due to the plethora of biochemical reactions inside our bodies at the cellular level, glucose metabolism being a prime example, a field of electromagnetic energy also surrounds our bodies. This makes the functioning of our bodies amenable to alteration by the effects of external resonance sources, whether infrasonic or electromagnetic, by interfering with our inherent resonance patterns. 

Infrasound in the environment

Sources of infrasound in the environment are myriad, both of man-made and natural origins. Natural sources include the wind, infrasonic waves generated in marine storms called microbaroms, geomagnetic activity, and small-scale seismic phenomenon. Transient, naturally occurring activities like the passage of meteors and auroral activity in the north can also lead to the generation of infrasonic signals. Cultural or man-made altercations include diesel engines, modern duct systems for heating and ventilation inside buildings, airplanes, large ships, and wind turbines. In addition, several incidents of persistent low-frequency rumblings have been reported in various cities across the world, which are commonly attributed to local industrial machinery though a clear source of the infrasound is usually not apparent.

Whatever the source, the effects of the interference of external infrasonic signals with those inherent to the human body can lead to a wide range of medical phenomena. Infrasonic waves have the remarkable ability to travel for longer distances as their absorption in the air is much less than audible sound. In addition to distance, the sound pressure the waves carry is another determinant of the biological effects of infrasound on humans. 

Adverse effects of prolonged exposure to low-frequency noise .

The observed effects of infrasonic signals include a feeling of sickness, nausea, behavior and mood changes, malaise, fatigue, and a medical syndrome called vibroacoustic disease. Some reports are anecdotal like the observation by ancient Greeks that people living in areas with persistent winds have specific medical symptoms or the findings that the blowing of wind in wet and cold weather, presumably due to a higher infrasound pressure, led to an increased incidence of sickness in residents of a high-rise Denmark hospital. In other cases, there is significant experimental evidence to support the adverse effects of infrasound on human health. It was reported by Bruel and Olesen, for example, that some people exposed to infrasound signals with a frequency of about 12 Hz and pressure of 58–110 dB felt ill within a short while of exposure. Others have noticed that university students sitting for a significant amount of time in lecture halls with large duct systems for ventilation had uneasy feelings of closeness and change in emotional behavior, which reverted when the motors were turned off. 

Vibroacoustic disease is a multisystem disorder that results from prolonged exposure to low-frequency noise — frequency of 500 Hz or lower. Initial symptoms include mood and behavior changes, which may progress to overt depression or aggressive behavior. Hearing loss, neurovascular disorders, and cardiac problems are part of the disease process. 

Not everything about external infrasonic vibrations is bad, however. There are therapeutic applications of low-frequency sound signals in the management of muscular disorders and chronic pain.

The generation, applications, and science of sound has been extensively studied. The infrasonic signals, the inaudible sound, on the other hand, is less so. Moreover, the full implications of the interaction of our infrasonic vibrations with those already present in the environment are not yet explored. 

The study of infrasonic vibrations provides an area of research that may hold important and unknown information about the workings of our bodies. Using sound therapy to balance the body’s system, a sound therapist intention is to give an extra layer of protection from the prolonged exposure to low-frequency noise from our environment .

Cells produce sound

Cells produce sound

For those practicing sound therapy the discovery that cells produce sound is no surprise.

James K Gimzewski, a chemist working at University of California, LA detected nano-oscillations produced by yeast cells using a special instrument called the atomic force microscope (AFM). 

Gimzewski and his colleague, Andrew Pelling, published their findings in 2004 in a prestigious scientific journal. The conducted experiments on simple barkers Yeats cells and what they found was fascinating. The cell wall of yeast oscillates at a fixed frequency which is temperature-dependent. The average frequency is about 1000 vibrations per second. Human ears have the ability to hear sounds with frequency in the range of 20 to 20,000 Hz. The volume of the sound produced by this nano-motion is too low to be heard by humans but its frequency falls within the audible range, which means it can be amplified to be audible. Gimzewski used commercially available software to convert this rhythmic cellular motion to an audible hum. 

The origin of the cellular oscillation seems to be the metabolic activity of the cell.

Inside a cell are various motor molecules, like dynein, actin, etc. They form the framework of the cell — the cytoskeleton — and are also used for transport inside the cell. It appears the sound detected by AFM is produced by the working of these molecular motors, just like moving parts in a car motor produce noise. Others have hinted towards ribosomes as a possible source. Ribosomes are cellular organelles involved in protein synthesis and are present in large numbers inside a cell. Gimzewski, however, disagrees with the ribosomes hypothesis and favors molecular motors as a source of the cellular noise. 

Other factors that alter the metabolic machinery of the cell influences the sound produced.  For example the vibration stops when a metabolic inhibitor acts upon the yeast cells, and its pitch increases when the cells are treated with alcohol. Yeast cells with certain genetic mutations, too, produce a discernibly different sound.

Using nanotechnology techniques, especially atomic force microscopy, the scope of work has been extended to mammalian cells including human cells — both healthy ones and cancer cells.

The work done by Gimzewski led to the formation of a new research field called Sonocytology — the study of sounds generated by cells. Finding relevant and practical applications for this newly found science has been the next logical step. 

A compelling aspect of sonocytology has been its potential use for the diagnosis of diseases. Michael Teitell was one of the first persons to explore this. Teitell, a pathologist at UCLA, thought of developing a database of acoustic signals from a variety of cancer cells which would then be used as a reference for comparing different cancers. Work done by other researchers has shown that diseased cells, especially cancerous ones, have different mechanical and elastic properties compared to normal cells. This means the sound signal generated by these cells would be different than the one produced by normal cells. 

The idea is that nano-oscillations produced by diseased cells will have a different acoustic pattern than that produced by healthy cells. 

Thus, listening to cells will enable physicians to detect diseases before they manifest clinically. In this case, the atomic force microscope (AFM) will, in effect, play the role of a nano stethoscope.

For the pioneers of this research field, the discovery of the phenomenon that cells generate rhythmic sound which can be heard by humans is an achievement in itself, even if the field doesn’t advance further. However, they are optimistic about finding broader use cases for it. The idea behind the use of sonocytology in clinical practice, especially oncology, is compelling although its practical utilization is yet to materialize.

The science of sonocytology is still young and according to researchers like Teitell would require many more years of research to be of clinical relevance. Its potential, however, seems promising. Our current methods of detecting cancer require the use of radiation imaging, histochemical stains, and molecular patterns. This means thousands of cancerous cells must be present in the sea of normal, healthy cells in order for them to be identifiable. 

With sonocytology, a single cell might be enough to diagnose cancer and even tell its prognosis. This could make the early detection of cancer possible. Compared to molecular methods which study a specific, limited aspect of a cell, listening to the sound of a cell will arguably provide a more wholesome picture of its overall health. The hope is that in the future, with sonocytology, early detection of cancer might become a reality.

Like every new field of research, sonocytology has its fair share of doubters, right from the get-go. Herman Gaub, a German physicist, pointed out that there could be more than one source of these sounds, and the possibility exists that they might arise from locations other than the cell membrane. To this, Gimzewski’s colleague, Pelling, agreed and hinted at more refined experiments. After a year of experimentation, they were confident that the source of the noise was indeed the cell itself. Some doubted the possibility that the technique could be applied to mammalian cells given their softer membranes compared to yeast. This has however been achieved successfully. The vibrations produced by human cells and especially cancer cells are, predictably, lower-pitched than that of yeast cells. There is a concern that the lower amplitude of sonic signals produced by human cells, especially cancer cells, might not be strong enough to be detectable and if detected, it may not be clear to yield meaningful information. 

The researchers hope, however, that the use of more sensitive and smaller probes in the AFM would address this concern.

The future of sonocytology

In the two decades since its discovery, sonocytology has advanced at a slower pace than some of its pioneers, like Teitell, might have hoped. With time, the hype has died down too. It is yet to carve a role for itself in the field of medicine. 

With advancements in nanotechnology and cytology, and our changing perspective regarding the diagnosis of human diseases, especially cancer, one could hope that, in the years to come, listening to the sound of cells would be one of our weapons in the perpetual fight against deadly diseases. 

Effects of vibration application

The recent years have seen a rising interest in the use of vibration platforms for achieving therapeutic or physical performance goals. Many devices are currently marketed for use in fitness or healthcare environments. Scientific data tend to be sparse on most of them, but many studies are under way.

There are large differences between the types of vibrations that these devices generate. Key descriptors of vibration devices include the frequency (measured in Hz; the number of Hz indicates the number of complete up-and-down movement cycles per second) and amplitude (measured in mm) of the vibration, as well as the direction of the vibration movement.4 The frequency of vibration devices typically ranges from a few Hz to 50Hz, with amplitudes ranging from a few micrometers to several millimeters. The force produced by the vibrating plate, and thus the ‘intensity’ of the treatment, increases with the frequency and the amplitude of the vibration.

The use of vibration stimulation for enhancing athletic performance and therapeutic use is considered an important matter of medical biology that has developed in the last three decades. Current evidence suggests that vibration is effective in enhancing musculoskeletal strength and power capacity and improving physical conditions in patients with related disorders such as osteoporosis and osteoarthritis, although the mechanisms mediating these effects are still not well known. The first use of vibration as an exercise was conducted by Russian scientists, who found that vibration was effective in enhancing strength in athletes. Subsequently, the effects of vibration application have been studied after acute and chronic exposure using different treatment protocols. Acute enhancement of mechanical power has been validated after vibration treatment applied with vibrating cables during bilateral biceps curl on a pulley machine.

Musculoskeletal structures respond to vibration because of the need to modulate muscle stiffness rapidly so as to accommodate the vibratory waves. This reaction is regulated by monosynapticand polysynaptic afferent pathways, which are capable of generating specific hormonal responses. These findings suggest that vibration could represent an effective exercise intervention for improving neuromuscular performance in sedentary and trained people.