Studying the Perception of Sound in Space: Granular Sounds Spatialized in a High-Order Ambisonics System

Abstract

Space is an important aspect of music composition that received little emphasis in certain periods of the history of Western music. However, in the twentieth century, electroacoustic music reintroduced this element by utilizing the different spatialization methods available. In this article, we discuss the methodology of analysis and the results of a study of the perception of sound in space involving sounds generated by granular synthesis that were spatialized in a high-order ambisonics system performed at CIRRMT’s Immersive Presence Laboratory at McGill University. We investigated two hypotheses of sound perception in space: 1) the variation of the granular synthesis parameters produces differences in the morphology of sounds perceived in their time-varying spatial distribution; and 2) the presence of more morphological sound variations when higher orders of ambisonics are employed, in addition to the generation of sound fields with more depth. In order to verify these hypotheses, we employed a method of analysis based on graphical representations of data derived from audio descriptors, such as graphical curves, a graphic representation of volume and phase space graphics. As a result, we observed that when higher orders of ambisonics are employed, the listener perceives more variations in frequency and intensity in sound spatialization, in addition to a preponderance of the decorrelation effect. Such effect is related to the presence of more diffuse sound fields.

Keywords

• sound perception in space. computer-aided musical analysis. high-order ambisonics. granular synthesis. electroacoustic music.