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This article is taken from a very old issue of the original CyberNoise magazine/digizine.
It may have been slightly altered e.g. to remove out of date contact details.

by Robert Scott Thompson

July 1993

Part 1: Psychoacoustics

"A body is after all a mystery. And how I start a body vibrating is extremely mysterious. Sonic vibrations don't only penetrate ears and skin. They penetrate the entire body, reaching the soul, the psychic center of perception. The esoteric only involves what cannot be described by means of existing scientific laws and rules. So the next step, time and again, is reinterpretations of the human body as an unbelievably complicated instrument for perception. That is why every genuine composition makes conscious something of this esoteric realm. This process is endless, and there will be more and more esotericism as knowledge and science become increasingly capable of revealing human beings as perceivers. Neurologists have been seeking for years for the pilot that must obviously exist in the human brain but are unable to find it. They can turn human beings upside down but are unable to discover how the human system is co-ordinated and centered. That will be discovered step by step, and the profundity of what remains unexplained will also gradually become apparent. I believe that the ratio between the amount concealed, the mysterious, and how much is known always remains largely the same. The further your knowledge extends, the more you discover that you can't explain."

Karlheinz Stockhausen - Stockhausen: Towards a Cosmic Music

Not long ago I was sitting in the cool Southern California living room of Japanese avant-garde maestro Joji Yuasa listening to and discussing new musical works. He presented his recent composition for large orchestra, Eye On Genesis (II), a massive, highly evocative musical statement. Widely revered for his brilliant orchestral compositions which evidence a keen modernist edge and stunning formal elegance, Yuasa remarked that this new work presented a crucial advancement of his musical language. As the title suggests, Eye On Genesis (II) is concerned with a kind of primordial sonic antiquity; in it Yuasa deals with sound elementally, directly - at once firm in his molding of an evolving soundscape, but also delicate in his graceful control of timbre and what he calls "musical sound space." While it is clearly an evocative statement of stunning power and crisp articulateness, Yuasa's new composition, as well as his idiosyncratic musical behaviors, are informed by a wide variety of extra-musical ideas. At the heart of his compositional method has been an over-riding concern for the individual veracity (the individual "life") of a sound, an attitude that has drawn him also to highly technical electroacoustic music.

Musical Futurism:

Somehow our conversation moved on to the broad subject of musical futurism, in the sense of attempting to perceive the quasi-utopian, nearly mystical evolution of human musical expression. I blithely asked Joji what he thought music would be like in 200 years (a modest future visioning I thought). He pondered this for a brief moment and replied "… I don't know about 200 years from now, but I think I know about 20 years from now." Yuasa believes, as he went on to explain, that the science of psychoacoustics will soon become vitally important as a compositional determinant, and that composers will be making more and more conscious, articulate use of the evolving theories involving our psychological relationship to musical expression. Sound composition (perhaps not what is currently heard as music but, rather, sound organized in time) will perhaps become more elemental, more iconic, and therefore, more essentially the defining aspect of musical art. Yuasa's idea is, as it turns out, not very far off the mark, and his time-table seems accurate as well. His advancement in the development of his musical language as outworked in Eye On Genesis (II) is largely informed by both subjective and objective knowledge about how music is perceived and processed by the human mind.

Psychological origins:

Psychoacoustics is a study that has been around since the time of antiquity it is only lately that it has become its own branch of the modern sciences, and a growing field of activity. It is the study of the effects of music on the central nervous system, the brain and the mind. It explores the influence of sound upon human feeling states and behavior.

Modern musicians, perhaps oriented toward popular music genres, working long hours with modular synthesis and tape recording equipment, have been working directly with elemental psychoacoustic ideas and directives for over thirty years - in some cases with complete knowledge and technical control, in some cases naively and intuitively.

Objective Metaphors: Psychoacoustics and Musical Futurism

The studies of acoustics and psychoacoustics will be considered by some to be overly complicated abstractions that seem not to have much to do with heartfelt, emotive musical expression. Yet, to a growing number of innovative and expressive composers an understanding of music perception and psychoacoustics is becoming an important tool in the creation of new musical compositions. In fact, the perspective provided by these sciences enable perhaps the most objective and exoteric viewpoints about musical sound and its organization to be expressed. While the image of the composer as a tortured creative genius shut away in his studio awaiting the blessings of the Muse may be romantic, electroacoustic music composition is primarily a technical activity which poses significant demands. Electroacoustic composers must balance intuitive processes with solid theoretical knowledge gleaned from the cutting edge of musical research. For composers such as Joji Yuasa this is the future of music.

Computers and Psychoacoustics:

Throughout the 20th century great strides have been made in understanding the physical and mechanical workings of the ear and the phenomena of hearing but, the study of the psychological effects of musical sound is relatively new.

What was needed was the technological means to create precisely measurable sound stimuli and to devise new experimental models. The development of the digital computer and computer music techniques (broadly referred to as software synthesis) has greatly facilitated the development of psychoacoustic research.

It was not until modern times that the true nature of sound, and the physical properties of the vibrating object (air column, string, plate) which produces it, could be studied in fine detail. The computer music workstation is to the study of sound what an electronmicroscope is to bio science. As it turns out, in its most technologically vital form, it is equally useful for analyzing, synthesizing and modifying sound. A crucial tool in the analytic study of the physical nature of sound is the Fourier Transform. This utilitarian device is in the form of mathematical equations which were devised by Jean Babtiste Fourier around 1800. In basic terms what the Fourier Transform states is that any time-varying complex sound may be de-synthesized into a number of sinusoidal waves (components, commonly known as harmonics or partials) with varying amplitude, frequency and phase angle. Once analyzed a complex sound may be synthesized from a number of sine wave oscillators with temporally varying amplitude, frequency and phase angle. Such analysis and re-synthesis is in the realm of Digital Signal Processing, and can be daunting at first to the uninitiated composer or electronic music synthesist. But, it is also an important wave for the future in sound synthesis. As computers become faster and more powerful they also become cheaper. Memory becomes cheaper and more reliable over time. In the very near future, say within Yuasa's 20 year prediction, real-time analysis and re-synthesis will be common. Sound will become a truly atomic entity which can be shaped and sculpted with fantastic precision.

Applications of Psychoacoustics:

Psychoacoustics has become over the last few years a highly sophisticated science. The experimental goal is the matching of mental phenomena (for example: conscious awareness states, emotional associations, mystical associative experiences) with sound objects, both composed and spontaneously created environmental sound complexes. While the classification and study of isolated acoustic objects, often musical sounds, is the domain of the science of acoustics, psychoacoustics attempts to relate organized sound to both perceived context and consciousness.

Both studies are central to the search for scientific or objective explanations for the musical sounds chosen by musicians of a given cultural group for artistic expression. Crucial information is now coming to light which may inform our continued compositional activity in significant ways. It has been suggested that our objective choice of particular sounds is rooted in very ancient origins. How ancient is difficult to assert. Some psychomusicologists (those who study the mystic esoteric origins of sounds and their inter-relationship within culture groups) refer to the intriguing notion that music, in the form of organized sound, replete with lexical and syntactic elements, predates the development of spoken language. Whether this is actually the case or not, music can be seen as a kind of primordial language that has at its core the propensity for merging esoteric and exoteric experience for the culture which defines it. Naturally, the study of music in a pragmatic, dispassionate scientific manner developed quickly in a number of music cultures. The study of music and the physical aspects of sound (both the esoteric and exoteric) was an integral aspect of the ancient musical societies found in China, India and the Middle East. As most of us know; the ancient Greeks developed an elaborate system of mathematical relationships (proportions) that had analogues in the formation of melodies as well as more general musical behaviors. This ancient experimentation formed the basis of our Western pitch, harmonic and rhythmic languages.

Metaphors and Processes:

The desire to find a scientific metaphor for musical activity has continued at a furious pace - even within the domain traditionally associated with the composer. An admittedly incomplete listing of approaches, as described by the technology of music composition, is the following: systematic chromaticism, atonality, serialism, set theory, aleatoric procedures, probability theory applications, stochastic music, chaos theory, DNA mapping, fractal geometry and musical symmetry studies. On the side of the pure science, affairs proceed slowly, methodically, experimentally. In fact, psychoacoustics is quite good at pointing out the important, gross aspects of musical behaviors that may elicit a fairly predictable psychological response from a listener; such as a 110dB loud, high pitched, metallic grating sound being found to be highly annoying to perhaps 99% of the human race, or that the sound of gently crashing ocean waves has a soothing meditative effect upon each of us. However, making fine distinctions in the perception of musical parameters (such as timbre) or explaining the process whereby music acts on the emotions of a listener are quite difficult problems. The staggering subtlety in both the actual, physical, nature of acoustic sound and the human cognition of sound (and resulting modification in behavior or feeling state) is both imposing and mystifying. The science of psychoacoustics has harnessed the latest high-tech tools to unlock the mysteries surrounding the relationship between consciousness and sound. Key research is sometimes on the elemental level, including studies of neural firing rates, the encoding of sound and pathways of auditory information transfer in the brain.

Limits to immediate utility:

The notion of matching culturally accepted ideals of musical beauty, for example, with auditory perception using the metaphor of mathematics has become a seductive problem. However, aesthetic experience cannot be quantified, nor, seemingly, can it be distilled to an essential process which can be triggered by a specific stimulus or set of stimuli. This is the insurmountable limitation of psychoacoustics. Our use of this information must remain modest for now, directed to a specific result, or a particular task - temporal structuring, direct sound synthesis, or the creation of spatial illusions (sonic holograms) are examples.

While we can only expect certain kinds of assistance from an understanding of basic psychoacoustics the importance of this study to the field of electroacoustic music, the development of our music cultures, and the work of the individual composer can not be understated. For the serious electroacoustic composer and creator of recorded music the studies of acoustics and psychoacoustics are indispensable to the development of a well-rounded foundation in the art form. Those who intuit the myriad applications of psychoacoustic theories and premises in their own creative expression will dig into the literature perhaps picking up some powerful digital signal processing tricks along the way.

Essential Publications is a trading name of Burning Helix s.r.o.
Destination Jarre © Graham Needham & Wayne Davis
CyberNoise © Graham Needham

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Essential Publications is a trading name of Burning Helix s.r.o.
Destination Jarre © Graham Needham & Wayne Davis
CyberNoise © Graham Needham