Perceptually significant features of granular processing

June 8th, 2006

Xenakis Legacies Symposium hosted by the University of Guelph in Ontario, Canada.

ABSTRACT – In Formalized Music (1963/1992), Iannis Xenakis proposed a method of using sonic grains to synthesize original sounds. His musical application of Gabor’s (1947) theory of “acoustical quanta” has since spawned a variety of electronic and computer music techniques chronicled by Curtis Roads in Microsound (2001). The most well known among these techniques are granular synthesis and granular processing.

In developing his proposal, Xenakis gave consideration to the limits of human auditory perception. He wanted to ensure the grains would not fall below the minimum duration and intensity that a listener could perceive. Xenakis also employed Fletcher-Munson equal-loudness contours as the basis for his screens. Although future research and development of granular techniques would continue to demonstrate an awareness of perceptual issues, direct empirical study of how listeners perceive granular sounds is missing from the literature.

The current author designed a series of three experiments to investigate how listeners perceive differences between granular processing examples. The findings were used to inform the design of a new graphical user interface (GUI) for granular processing. The resulting GUI helped to verify this study’s conclusions by successfully demonstrating their practical application to software development. The author will demonstrate the GUI’s unique controls for managing randomization and its feedback display for monitoring differences between the control input and audio output.

The author will conclude by addressing future directions in which this research may continue. Processing differences for the current experiments were limited to grain duration and grain period in order to provide a necessary focus. Additional parameters for testing in future experiments will be identified, as well as experimental methods besides MDS that may be used to approach this same inquiry and strengthen the current study’s findings.

One Response to “Perceptually significant features of granular processing”

  1. [...] June 2006, I traveled to Ontario to participate in a symposium on the legacy of composer Iannis Xenakis, in addition to doing a little sightseeing with my family. [...]

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