Sound spatialisation using Ambisonic

Oscar Pablo Di Liscia

Carrera de Composición con Medios Electroacústicos
Universidad Nacional de Quilmes
Buenos Aires


The main resource to simulate location of a sound source is to try to fool our auditory system by creating phantom sources. Those are sounds that do not come from where the virtual source seems to be, but gives to our auditory system the impression that the sound source is located at some -real- point in the space.

The procedure more commonly involved in the simulation of phantom sources is referred to as intensity panning. Though widely used, intensity panning is at present being strongly criticized because of perceptual limitations.

Some British recording engineers -mainly Michael Gerzon- developed a technique called Ambisonic (which is a registered Trademark of Nimbus Communications International), widely used at present. Ambisonic attempts to overcome the limitations above mentioned by encoding the signal on the same way that a special microphone would record it. The decoding procedure attempts to recreate the wave front that the microphone "had listened" for a given array of loudspeakers.

The computer program WDSPA uses this technique -among others- to spatialise digital sound.

This paper discusses both the Ambisonic technique in comparison with intensity panning, and it implementation on the program WDSPA.

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