A spatialized additive synthesizer


Authors: Verron C., Aramaki M., Kronland-Martinet R., Pallone G.
Publication Date: December 2007
Journal: In Proceedings of the inaugural International Conference Music Communication Science (ICoMCS), Sydney, Australia, 5-7 December 2007 (pp.167-171)


In virtual auditory environments, sound generation is typically based on a two-stage approach: synthesizing a monophonic signal, implicitly equivalent to a point source, and simulating the acoustic space. The directivity, spatial distribution and position of the source can be simulated thanks to signal processing applied to the monophonic sound. A one-stage synthesis/spatialization approach, taking into account both timbre and spatial attributes of the source as low-level parameters, would achieve a better computational efficiency essential for real-time audio synthesis in interactive environments. Such approach involves a careful examination of sound synthesis and spatialization techniques to reveal how they can be connected together. This paper concentrates on the sinusoidal sound model and 3D positional audio rendering methods. We present a real-time algorithm that combines Inverse Fast Fourier Transform (FFT-1) synthesis and directional encoding to generate sounds whose sinusoidal components can be independently positioned in space. In addition to the traditional frequency-amplitude-phase parameter set, partials positions are used to drive the synthesis engine. Audio rendering can be achieved on a multispeaker setup, or in binaural over headphones, depending on the available reproduction system.