SPATIAL ENCODING AND DECODING OF FOCUSED VIRTUAL SOUND SOURCES
Jens Ahrens, Sascha Spors · 2009
Abstract: Spatial encoding refers to the representation of a sound field which allows storage and transmission of the latter. In the Ambisonics context, sound fields can be spatially encoded when their spherical wave spectrum is bandlimited. The process of deriving appropriate loudspeaker driving signals in order to reproduce an encoded sound field is known as spatial decoding. Care has to be taken when virtual sound sources are positioned such that they appear inside a given loudspeaker setup for which they are decoded. The properties of the mathematical formulation make the reproduced sound field deviate strongly from the desired one in certain receiver positions. In this contribution we demonstrate by means of a two-dimensional scenario how the concept of focused virtual sound sources can be applied in order to optimize the reproduction accuracy. Key words: sound field reproduction, higher order Ambisonics, circular harmonics, focused sources 1