University System of Maryland

Visisonics Corporation

Nail A Gumerov

Ramani Duraiswami

Adam O'Donovan

Dmitry N Zotkin

Bowen Zhi

A spatial-audio recording system includes a processor, and instructions stored in a computer-readable medium that, when read by the processor, cause the processor to perform operations. The operations include retrieving audio data recorded at a number of microphones, determining a recorded signal vector based on the audio data, and initializing values for an operator. The operations further include determining a plurality of waves from directions by performing operations comprising iteratively, until an exit condition is satisfied: initializing or incrementing an index 'i'; determining an ith direction using the operator; and updating the operator to correspond to the ith iteration.

Systems and methods for analyzing multichannel wave inputs

A spatial-audio recording system includes a spatial-audio recording device including a plurality of microphones, and a computing device. The computing device is configured to determine a plane-wave transfer function for the spatial-audio recording device based on a physical shape of the spatial-audio recording device and to expand the plane-wave transfer function to generate a spherical-harmonics transfer function corresponding to the plane-wave transfer function. The computing device is further configured to retrieve a plurality of signals captured by the microphones, determine spherical-harmonics coefficients for an audio signal based on the plurality of captured signals and the spherical-harmonics transfer function, and generate the audio signal based on the determined spherical-harmonics coefficients.

Audio signal processor and generator

A method comprises providing at least one processing unit comprising a decomposing section and a playback section; receiving, at the decomposing section, audio data generated via an array of microphones, the audio data representing an acoustic scene; decomposing the audio data into a plurality of signals representing components of the acoustic scene arriving from a plurality of directions, using the decomposing section; and rendering the audio components for a listener based on the plurality of directions of the audio components, using the playback section.

Audio camera using microphone arrays for real time capture of audio images and method for jointly processing the audio images with video images

Spherical microphone arrays provide an ability to compute the acoustical intensity corresponding to different spatial directions in a given frame of audio data. These intensities may be exhibited as an image and these images are generated at a high frame rate to achieve a video image if the data capture and intensity computations can be performed sufficiently quickly, thereby creating a frame-rate audio camera. A description is provided herein regarding how such a camera is built and the processing done sufficiently quickly using graphics processors. The joint processing of and captured frame-rate audio and video images enables applications such as visual identification of noise sources, beamforming and noise-suppression in video conferencing and others, by accounting for the spatial differences in the location of the audio and the video cameras. Based on the recognition that the spherical array can be viewed as a central projection camera, such joint analysis can be performed.

Head Related Transfer Functions (HRTFs) of an individual are measured in rapid fashion in an arrangement where a sound source is positioned in the individual's ear channel, while microphones are arranged in the microphone array enveloping the individual's head. The pressure waves generated by the sounds emanating from the sound source reach the microphones and are converted into corresponding electrical signals which are further processed in a processing system to extract HRTFs, which may then be used to synthesize a spatial audio scene. The acoustic field generated by the sounds from the sound source can be evaluated at any desired point inside or outside the microphone array.

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Elkridge, MD, United States of America

Nail A Gumerov