Northwestern Polytechnical University

Jilu Jin

Jingdong Chen

Gongping Huang

Jacob Benesty

Xuehan Wang

Yuzhu Wang

Xueqin Luo

Xudong Zhao

A concentric circular microphone array (CCMA) may include a number of omnidirectional microphones and an equal number of directional microphones, wherein the omnidirectional microphones and the directional microphones form a plurality of concentric rings on a substantially planar platform. Each of the plurality of concentric rings includes a subset of the omnidirectional microphones and a subset of the directional microphones (e.g., arranged in mixed pairs of microphones). Responsive to a sound source, the omnidirectional microphones and the directional microphones may respectively generate first and second electronic signals. A target beampattern of Norder may be specified for the CCMA. An Norder beamformer for the CCMA, that is steerable in a three-dimensional space including the sound source, may be determined based on the specified target beampattern. The beamformer may be executed to calculate an estimate of the sound source based on the first electronic signals and the second electronic signals.

Concentric circular microphone arrays with 3D steerable beamformers

A binaural beamformer comprising two beamforming filters may be communicatively coupled to a microphone array to generates two beamforming outputs, one for the left ear and the other for the right ear. The beamforming filters may be configured in such a way that they are orthogonal to each other to make white noise components in the binaural outputs substantially uncorrelated and desired signal components in the binaural outputs highly correlated. As a result, the human auditory system may better separate the desired signal from white noise and intelligibility of the desired signal may be improved.

Binaural beamforming microphone array

An Norder linear differential microphone array (LDMA) with a steerable beamformer may be constructed by specifying a target beampattern for the LDMA at a steering angle &#x3b8;. An Norder polynomial associated with the target beampattern may then be generated. A relationship between the nulls of the polynomial and the steering angle &#x3b8; is determined and then a value of one of the nulls is determined based on N&#x2212;1 assigned values for the other nulls and the determined relationship between the nulls of the polynomial and the steering angle &#x3b8;. The steerable beamformer may be generated based on the determined null value and the N&#x2212;1 assigned null values. The N&#x2212;1 assigned null values may be associated with the N&#x2212;1 nulls of the polynomial that are of less than Norder and the determined null value may be associated with the null of the polynomial that is of Norder.

Linear differential microphone arrays with steerable beamformers

An Norder linear differential microphone array (LDMA) including at most M microphones, where M is greater than N, is constructed by identifying a number K of combinations of at least (N+1) of the M microphones. A target cost function is specified based on at least one of a directivity factor, a beampattern, or a white noise gain associated with the LDMA. For each frequency band of a plurality of frequency bands: an optimal combination of microphones, from the K combinations, is determined based on an evaluation of the target cost function for the band and beamforming is performed using the determined optimal combination for the band. A union of the optimal combinations of microphones for the plurality of bands may be determined and the LDMA may be constructed, using microphones in the union, based on an evaluation of the target cost function across the plurality of bands.

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Shanxi, China

Jilu Jin