The term `psychoacoustics’ essentially refers to the modern study on the way sound emanations are perceived by human beings. The study includes how we listen, our psychological responses, and the physiological impact of music and sound on our nervous system. In the realm of psychoacoustics, the terms music, sound, frequency, vibrations etc. become interchangeable, as the study is aimed at dissecting the listening experience.
Sound Perception: Neurological and Psychological Aspects
However, there is an important distinction here as there is a possible difference between a psychological and a neurological perception of sounds. Recent studies with brain-waves indicate that slightly detuned tones can cause them (brain waves) either to accelerate or retard their rhythms. Additionally, soundtracks that are filtered and gated by the sound engineers (this is a sophisticated engineering process) tend to create a random sonic event. It is now known to trigger an active listening response (thus tonifying the auditory mechanism), which also includes the tiny muscles of the middle ear. As a result, sounds could be perceived with more accuracy. This also could result in improvement of one’s speech and communication skills. It is reported that while a psychological response may occur with filtered and gated sounds, or detuned tones, the primary effect is physiological (or neurological) in nature.
Recent research on the neurological component of sound is currently attracting many students and researchers to the field of psychoacoustics. A growing school of thought – based on the teachings of the French physician, Alfred Tomatis – values the examination of both neurological and psychological effects of resonance and frequencies on the human body and a comparative research in these two areas will no doubt, give us all a clear insights on the ancient Indian understanding of sound (`nada’) as an agent that helps in altering the level of the human consciousness, through yogic practices or sadhana.
Filtration /Gating (F/G) Technique
Dr. Alfred Tomatis is widely recognized for his contribution in the field of psychoacoustics. Tomatis adapted his techniques to target diverse disorders including auditory processing problems, dyslexia, learning disabilities, attention deficit disorders, autism, and sensory integration and motor-skill difficulties. The Tomatis Method uses recordings by Mozart and Gregorian Chant as well as of the patient’s mother’s voice. Tomatis’ use of Mozart is different from what is being popularized as the Mozart Effect popularized by the American author and music researcher Don Campbell. Although Tomatis coined this phrase, his sense was never related to claims that listening to Mozart could increase intelligence, for example. His clinics worldwide have now honed the “Filtration/ Gating” (F/G) Technique. By gradually gating and filtering out the lower range of music (sometimes up to 8000 Hz), and then adding the frequencies back in, a retraining of the auditory processing system is attempted. The impact of such filtration and gating is experienced on a psychological, neurodevelopmental, and even physical level. It is now felt that the application of sound stimulation could be helpful in the remediation of many neurodevelopmental issues. Children and adults with learning/attention difficulties, developmental delays, auditory processing problems, sensory integration and perceptual challenges are widely-reported to have experienced profound improvement.
Binaural Beat Frequencies (BBFs)
BBFs is yet another approach to sound processing. By listening through stereo headphones to slightly detuned tones (i.e., sound frequencies that differ by a prescribed number of Hz), sonic brainwave entrainment is found to take place. It is observed that by facilitating a specific range of brainwave states, one could assist in arenas such as pain reduction, enhanced creativity, or even accelerated learning. Binaural beats in the beta frequency have been associated with increased concentration or alertness, vividness, and clarity.
In recent years, Joshua Leeds, another researcher, has further expanded and confirmed the theories of Tomatis. For this, Joshua Leeds had employed the latest technologies involving the technique of computerized measurement of brainwaves, heart rates, and other body pulses. These developments in the field of psychoacoustics have now extended new avenues for the scientists and researchers to explore the more specific (and more clear) areas of music application. This would immensely benefit people especially with the possibilities that have emerged in recent times, e.g., neuro-feedback and other computer programs. It is the possibility to measure scientifically that has brought in this specificity in future research areas. Thus, the employment of sound and music can now become more precise as music can be explored for its symptom-specific, application-specific, and environment-specific role for the wider acceptance by science.
Neuro-Physical Healing Processes Triggered by Music
In this context, there can be three neuro-physical healing processes that can be triggered by music applications.
1. As in `aalaap’ (for instance) music could be nonverbal; it can therefore move through the brain’s auditory cortex directly to the center of the limbic system. As the limbic system governs emotional experiences and basic metabolic responses such as body temperature, blood pressure and heart rate, the music on entering the brain can help create new neural pathways.
2. Music is also now a widely-accepted activator of the flow of stored memory and imagined material across the corpus callosum (bridge between left and right hemispheres of the brain). As a result, it can be proactive for their harmonious functioning, resulting in the stimulation of the immune mechanism in the body.
3. Music is also considered for its role as something that excites peptides in the brain. This excitation is also the cause for stimulating the production of ‘feel good’ chemicals, the endorphins. Being what they are — the natural opiates, secreted by the hypothalamus- the listener is assured of a ‘drugless’ and natural euphoria, shifting his or her moods — at least temporarily!
References
Gilkey, R.H., and Timothy R Anderson, 1997. Binaural and Spatial Hearing in Real and Virtual Environments, Lawrence Erlbaum Associates
Leeds, Joshua,. 1997, Sonic Alchemy, InnerSong Press. Sairam, Trimurthy, V. 2007.
Self-Music Therapy, Nada Centre for Music Therapy.
Tomatis, Alfred, 1991. The Conscious Ear, Station Hill Press
Edited by Geeta Shreedar, September 3, 2021