Signal Processing Seminar

3D direction of arrival estimation of multiple audio sources with spherical microphone arrays

Despoina Pavlidi
University of Crete, Department of Computer Science, Heraklion, Crete, Greece

Abstract: Direction of arrival estimation plays a central role in numerous signal-processing applications, such as smart home automation, surveillance systems, etc. Until recently the research community was mainly interested in single-dimensional direction of arrival (DOA) estimation by deploying linear or planar microphone arrays. Nowadays the focus has turned also towards spherical microphone arrays, which enable the more accurate capturing of the acoustic wavefield, hence enabling two-dimensional DOA estimation, i.e., the azimuth and elevation of an active audio source. In this talk we will present our proposed methodologies for DOA estimation in the 3D space. Our first proposed method relies on energetic analysis. We estimate the sound intensity vector on selected time-frequency elements of the spectrum and post-process the estimates utilizing 2D histogram representations. We enhance our approach by applying beamforming around local intensity vector directions. We call our hybrid approach spatially constrained beamforming (SCB). Our second proposed method improves the performance of two grid-based approaches, namely the steered response power (SRP) and the multiple signal classification (MUSIC) algorithm, both formulated in the spherical harmonic domain. We propose to derive local DOA estimates from the power map for SRP and the pseudospectrum for MUSIC. From these local DOA estimates we form a 2D histogram that we process to derive the final multiple sources directions.

Overview of Signal Processing Seminar