Sound Research WIKINDX

Granular synthesis involves generating thousands of tiny sonic events known as grains. These grains can be considered the building blocks of sound, or atomic sound particles. They can be combined to generate new sounds, timbres, or sonic textures. Granular synthesis is unique because it collapses the time and frequency domains within the concept of the grain. This collapse in domain allows the limits of sonic perception to be exploited.

 

The textures that can be created using granular synthesis are very exciting as they allow for a soundscape that is totally controllable by the composer. Not only is the composer in control of each timbre, each duration, and each pitch within the piece, but also how these parts interact with each other. This advantage of complete controllability of all aspects of the texture is carried out at the macro, as well as the micro level. Unfortunately such a large amount of control makes it difficult to keep control of all the levels. This is overcome by using statistical forms of control.

 

Computer synthesis has been common for a long time now. There are many forms of computer synthesis including additive synthesis, subtractive synthesis, distortion synthesis, frequency modulation, amplitude modulation, formant (FOF) synthesis, dynamic stochastic synthesis, graphic synthesis, interpolation synthesis, table-lookup synthesis, time-varying wave form synthesis, waveshaping synthesis, and window function synthesis (Roads 1996a). Granular synthesis could be seen as a form of additive synthesis but its approach and sonic results are quite different from additive synthesis.

 

Until very recently the techniques and means associated with granular synthesis were not available to many people. This was due to the nature of granular synthesis, in that it can contain literally thousands of parameterized events just to specify one second of sound. Processing such large amounts of data required the work of mainframe computers equipped with a digital to analog converter (DAC). For many years Bell Telephone Laboratory in the USA was the only place capable of any type of sound synthesis (Roads 1996a: 87). Later there were facilities available at IRCAM in France (Risset 1985:11), University of California (Roads 1996a: 169), and Massachusetts Institute of Technology (Roads 1996a: 547).

 

Even with such large computers the processing could take a week just to get basic results. Until about 1990 the most prominent people involved with granular synthesis were Iannis Xenakis, Curtis Roads, Barry Truax, Douglas Jones and Thomas Parks. Xenakis actually completed his granular composition without the aid of a computer. This was achieved by splicing and rearranging magnetic audio tape, an even more difficult process (Roads 1996a: 169). Curtis Roads spent 10 years on a number of mainframe computers creating a 10 minute composition called nscor (Roads 1985: 165-167).

 

Computers have come a long way since 1990. They can process data at extremely high speeds. They are all equipped to perform sound synthesis techniques including sampling synthesis. They are small enough to use in the home. This step forward in computer technology has meant that granular synthesis can now be realised everywhere, including some commercial synths. As people come to learn about granular synthesis techniques there is a growing understanding and popularity of it's usefulness."