Abstract: A method of signal processing includes calculating a range based on information from a reflected ultrasonic signal. Based on the calculated range, one among a plurality of direction-of-arrival (DOA) estimation operations is selected. The method also includes performing the selected operation to calculate an estimated direction of arrival (DOA) of an audio-frequency component of a multichannel signal. Examples of DOA estimation operations include operations based on phase differences between channels of the multichannel signal and operations based on a difference in gain between signals that are based on channels of the multichannel signal.

Abstract: A mobile platform includes a microphone array and is capable of implementing beamforming to amplify or suppress audio information from a sound source. The sound source is indicated through a user input, such as pointing the mobile platform in the direction of the sound source or through a touch screen display interface. The mobile platform further includes orientation sensors capable of detecting movement of the mobile platform. When the mobile platform moves with respect to the sound source, the beamforming is adjusted based on the data from the orientation sensors so that beamforming is continuously implemented in the direction of the sound source. The audio information from the sound source may be included or suppressed from a telephone or video-telephony conversation. Images or video from a camera may be likewise controlled based on the data from the orientation sensors.

Abstract: Systems, methods, apparatus, and machine-readable media for voice activity detection in a single-channel or multichannel audio signal are disclosed.

Abstract: Decomposition of a multichannel signal using direction-of-arrival estimation, a basis function inventory, and a sparse recovery technique is disclosed.

Abstract: Systems, methods, apparatus, and machine-readable media for orientation-sensitive selection and/or preservation of a recording direction using a multi-microphone setup are described.

Abstract: Systems, methods, apparatus, and machine-readable media for detecting head movement based on recorded sound signals are described.

Abstract: Systems, methods, apparatus, and machine-readable media for three-dimensional sound recording and reproduction using a multi-microphone setup are described.

Abstract: Systems, methods, and apparatus for processing an M-channel input signal are described that include outputting a signal produced by a selected one among a plurality of spatial separation filters. Applications to separating an acoustic signal from a noisy environment are described, and configurations that may be implemented on a multi-microphone handheld device are also described.

Abstract: Decomposition of a multi-source signal using a basis function inventory and a sparse recovery technique is disclosed.

Abstract: An apparatus for multichannel signal processing separates signal components from different acoustic sources by initializing a separation filter bank with beams in the estimated source directions, adapting the separation filter bank under specified constraints, and normalizing an adapted solution based on a maximum response with respect to direction. Such an apparatus may be used to separate signal components from sources that are close to one another in the far field of the microphone array.

Abstract: Methods, apparatus, and systems for source separation include a converged plurality of coefficient values that is based on each of a plurality of M-channel signals. Each of the plurality of M-channel signals is based on signals produced by M transducers in response to at least one information source and at least one interference source. In some examples, the converged plurality of coefficient values is used to filter an M-channel signal to produce an information output signal and an interference output signal.

Abstract: A disclosed method selects a plurality of fewer than all of the channels of a multichannel signal, based on information relating to the direction of arrival of at least one frequency component of the multichannel signal.

Abstract: Methods, systems, and apparatus for using a psychoacoustic-bass-enhanced signal to drive an array of loudspeakers are disclosed.

Abstract: A multi-microphone system performs location-selective processing of an acoustic signal, wherein source location is indicated by directions of arrival relative to microphone pairs at opposite sides of a midsagittal plane of a user's head.

Abstract: Methods and apparatus for generating an anti-noise signal and equalizing a reproduced audio signal (e.g., a far-end telephone signal) are described, wherein the generating and the equalizing are both based on information from an acoustic error signal.

Abstract: A noise cancelling headset for voice communications contains a microphone at each of the user's ears and a voice microphone. The headset shares the use of the ear microphones for improving signal-to-noise ratio on both the transmit path and the receive path.

Abstract: Implementations and applications are disclosed for detection of a transition in a voice activity state of an audio signal, based on a change in energy that is consistent in time across a range of frequencies of the signal.

Abstract: A headset is constructed to generate an acoustically distinct speech signal in a noisy acoustic environment. The headset positions a pair of spaced-apart microphones near a user's mouth. The microphones each receive the user's speech, and also receive acoustic environmental noise. The microphone signals, which have both a noise and information component, are received into a separation process. The separation process generates a speech signal that has a substantial reduced noise component. The speech signal is then processed for transmission. In one example, the transmission process includes sending the speech signal to a local control module using a Bluetooth radio.

Abstract: Systems, methods, apparatus, and computer-readable media for dereverberation of a multimicrophone signal combine use of a directionally selective processing operation (e.g., beamforming) with an inverse filter trained on a separated reverberation estimate that is obtained using a decorrelation operation (e.g., a blind source separation operation).

Abstract: Based on phase differences between corresponding frequency components of different channels of a multichannel signal, a measure of directional coherency is calculated. Application of such a measure to voice activity detection and noise reduction are also disclosed.