Concentric circular microphone arrays with 3d steerable beamformers

A method for beamforming with a concentric circular microphone array (CCMA), comprising:

• obtaining, by a processing device responsive to a sound source, first electronic signals generated by a first number of omnidirectional microphones and second electronic signals generated by a second number of directional microphones, wherein the omnidirectional microphones and the directional microphones are arranged on a substantially planar platform, forming a plurality of concentric rings, and wherein each of the plurality of rings comprises a subset of the omnidirectional microphones and a subset of the directional microphones;
• specifying a target beampattern of Nth order for the CCMA, wherein N is an integer;
• determining an Nth order beamformer for the CCMA, that is steerable in a three-dimensional space, based on the target beampattern;
• and
• executing the beamformer to calculate an estimate of the sound source based on the first electronic signals and the second electronic signals.

A concentric circular microphone array (CCMA), comprising:

• a number (N) of omnidirectional microphones and an equal number (N) of directional microphones, wherein:
• the omnidirectional microphones and the directional microphones are arranged in mixed pairs on a substantially planar platform, forming a plurality of concentric rings, each mixed pair comprising one of the omnidirectional microphones and one of the directional microphones;
• each of the directional microphones is associated with a dipole-shaped beampattern aligned in a direction perpendicular to the planar platform;
• each of the plurality of rings comprises a subset of the mixed pairs of omnidirectional microphones and directional microphones.