Ph.D. thesis – Examples | Miguel Negrão

Parameter Field Spatialization:The development of a technique and software library for immersive spatial audio

2016

Abstract

This thesis describes parameter field spatialization, a novel technique for creating and controlling spatial sound patterns formed along a surface, when working with sound synthesis and signal processing in a computer-music environment. Its main purpose is the creation of spatially-dynamic immersive sources in electroacoustic composition. This technique generates multiple decorrelated signals from a given sound process definition, which when spatialized at different locations can create a single enveloping auditory event with large width and heigth. By modulating parameters of the sound process differently for each signal it is possible to create a spatial surface pattern. The modulation signals are generated based on a mathematical model which assumes a surface encompassing all the loudspeakers and describes an abstract pattern in this surface through a mathematical function of time and surface coordinates, called parameter field. This research investigates whether parameter field spatialization can successfully create and precisely control spatial surface patterns, and how these patterns can be made into a compositional parameter in computer music.

Abstract The technique was implemented in ImmLib, a software library for the SuperCollider audio-synthesis environment. Several specific examples of the combination of parameter fields with sound processes were investigated from a perceptual point of view, in listening sessions using two loudspeaker systems, one spherical and the other a vertical rectangular grid. A group of composers was invited to use the software for their own work, producing three pieces presented in public, which were analysed regarding the use of the technique. From this practical work findings relating to the most effective strategies regarding the use of parameter fields were outlined.