Four-dimensional sound source recovery from arbitrary acoustic arrays

Current acoustical recording systems provide limited flexibility in sound recovery; single microphone systems reconstruct sound over time at a single spatial location, or "one-dimensional" (temporal) recording, whereas arrays may provide isolation in an azimuthal direction of along a pencil beam (two or three dimensional, respectively). Full four-dimensional recovery of a source at any spatial location, particularly using an arbitrary, modest array of acoustical sensors, enables many new applications. A modified frequency-domain MVDR adaptive beamforming algorithm especially tailored for high-performance recovery of nonstationary targets in similar background demonstrates in simulation SIR gains of over 12 dB for speech-in-speech acoustic target recovery, even in situations with more sources than sensors.