CONTROLLED CHAOS AND OTHER SOUND SYNTHESIS TECHNIQUES A THESIS SUBMITTED TO THE FACULTY IN CANDIDACY FOR THE DEGREE OF BACHELOR OF SCIENCE BY KIMO JOHNSON UNIVERSITY OF NEW HAMPSHIRE DURHAM, NEW HAMPSHIRE

1 INTRODUCTION Sound synthesis is a field that bridges the disciplines of music, physics, mathematics and psychoacoustics. Researchers from all of these fields study and use sound synthesis for different reasons. For example, musicians researching sound synthesis are often trying to find interesting sounds for compositional or artistic purposes. They look for sounds with a depth similar to those of natural instruments and their trained ears are often sensitive to sounds that are too artificial. Physicists and mathematicians are curious about how instruments work and the laws governing their behavior. They use sound synthesis to test their hypotheses and models of instruments. Researchers of psychoacoustics, on the other hand, are interested in how the ear and mind interact when we hear a sound. They use sound synthesis to help them examine human perception. This does not mean that musicians are not interested in perception or that psychoacousticians are not interested in how instruments work. On the contrary, when one begins to study a particular aspect of sound synthesis, one finds that questions related to the other fields of study need to be answered as well. The goal of this thesis was to synthesize instrument sounds using a new synthesis technique derived from work in chaotic communications. My first step towards this goal was to learn classic synthesis techniques that have been both successful and unsuccessful. This information taught me about the problems that arise when trying to synthesize sound. This also put me face to face with the relationship between the physical and psychological interpretations of sound. I conducted several experiments to determine how I perceived certain sounds when I knew the physical components involved. These experiments gave me first hand knowledge about the intricacies of human perception. My interest in music was also important to my 2 research. I judged the synthesized instrument tones against my experience with natural instruments. While working on this thesis, I found it necessary to research the physics, mathematics and psychoacoustics involved in sound synthesis and I have included my findings in the Background Information chapter. The final step towards my goal was to use the knowledge and experience I had gained with other synthesis techniques to help me synthesize sounds using controlled chaos. 3 ORGANIZATION OF THE THESIS The first section of this thesis provides background information about both the physical and psychological aspects of sound. I only discuss those aspects of sound …