Resolving spatial sampling effects in parametric directional filtering

Directional Audio Coding (DirAC) represents an efficient scheme to analyze and reproduce spatial sound; the coded stream consists of a single-channel audio signal and few parameters. Estimation of these parameters ideally relies on figure-of-eight microphones and one omnidirectional microphone. The figure-of-eight directivity can be efficiently approximated by first-order differential microphone arrays. However, due to spatial sampling, there are considerable deviations from the required directivity at high frequencies. These deviations lead to incorrect spatial parameter estimates; especially, the instantaneous direction-of-arrival (DOA) becomes biased and – beyond a certain aliasing frequency – ambiguous. Parameters like the DOA drive subsequent processing units, e. g., for spatial filtering. In this paper we propose a novel strategy to compensate bias and ambiguity not directly w. r. t. the DOA but the output parameters of a spatial filtering processing unit. Simulation ...

• Type: Journal
• Year: 2011
• Where: ICASSP
• Authors: Markus Kallinger, Michael Buerger, Oliver Thiergart, Fabian Kuech, Dirk Mahne
• Keywords: ICASSP 2011, Parameters, Processing Unit, Signal Processing, Spatial