Cellular Automata Synthesis of Acoustic Particles

Eduardo Reck Miranda


In this report we study Chaosynth: a new sound synthesis system, which uses a cellular automaton to produce sounds.

The sounds produced by Chaosynth can resemble the sounds of flowing water, bird calls and insect-like noises. The system also produces sounds that cannot be found in the "real" acoustic world.

Chaosynth generates a large amount of short acoustic events, or particles, in order to form larger, complex sound events. The synthesis method of Chaosynth is inspired by the granular synthesis technique [1, 2, 3, 4, 5]. Most granular synthesis techniques use stochastic methods to control the formation of sound events. Chaosynth, however, uses a cellular automaton [6].

The first part of the report introduces the basics of granular synthesis and explains how Chaosynth's technique works. We then introduce the basics of cellular automata and present ChaOs: the cellular automaton used in Chaosynth. We complete this first part with our conclusions and suggestions for further work. The second part continues by illustrating some functional aspects of the system through examples and studies how to set up the system in order to produce various sorts of sounds. We give a commentary on Olivine Trees: a piece of electroacoustic music specifically composed using sounds produced by Chaosynth, during the author's TRACS Research Fellowship at EPCC (Edinburgh Parallel Computing Centre) in Scotland, UK.

The author would like to thank Robert Fletcher (of EPCC) and Peter Nelson (of Edinburgh University's Music Department) for their support during the earlier stages of this reasearch. The first experimental prototype of Chaosynth (the one that is discussed in part 2 of this report) was implemented by Martin Westhead in 1993.


The System

Granular Synthesis and Chaosynth

The basics of cellular automata

The ChaOs cellular automaton and the metaphor

The algorithm

The mapping technique

The Chaosynth program



Sound Design Using Chaosynth

Sound design using Chaosynth

The definition of frequency sets and subsets

The synthesis of the subsets

The role of other parameters

The rate of depolarisation

The duration of the sonic particles

The amount of oscillators and the dimension of the grid



Standard Chaosynth's Csound orchestra file

An example Csound score file

User manual

ftp Unix (Silicon Graphics) version

ftp Linux version for PC

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