Broadcom Corporation

Avago Technologies General IP (singapore) Pte. Ltd.

Franck Beaucoup

Wilfrid Paul LeBlanc

Aleksander Radisavljevic

Wilf LeBlanc

Taro Umezawa

Embodiments of the present disclosure provide systems and methods for source localization using a microphone array. Such an embodiment, among others, utilizes circuitry to process audio signals and microphone signals to remove an echo (produced by a nearby loudspeaker) from the microphone signals using a plurality of adaptive echo cancellation filters. Location information is then determined for the loudspeaker based on the plurality of adaptive echo cancellation filters used to remove the echo.

Loudspeaker localization with a microphone array

Methods, systems, and apparatuses are described for performing acoustic echo cancellation with internal upmixing that allow for a more effective handling of acoustic echo cancellation of audio components that are provided via different channels. In an embodiment in which audio is played back using two loudspeakers, audio components that are panned equally among the loudspeakers form a 'phantom center image.' Acoustic echo cancellation is performed by initially upmixing the different channels to internally create modified versions of these channels and a virtual channel representative of the phantom center image. Each of these channels is passed through a respective adaptive filter that is configured to estimate an acoustic echo produced by each respective channel. These estimates are then subtracted from the signal received from one or more microphones (or from a signal obtained by combining multiple microphone signals) to suppress or eliminate the acoustic echo.

Acoustic echo cancellation with internal upmixing

Methods, systems, and apparatus for controlling audio signal processing are described herein. In accordance with certain embodiments, a measure of coupling between at least one microphone and one speaker associated with an audio device is obtained. The measure of coupling may be used to control audio signal processing, such as sidetone generation and application of multi-channel decorrelation to the audio signal.

Signal processing control in an audio device

A system performs residual echo suppression on a microphone signal that receives, e.g., voice commands, and that is exposed to echo from multiple speakers. An example is a smartphone that receives voice commands while the smartphone is playing music through stereo speakers. The system estimates residual echo level in different ways, and determines which estimate to use. The technique responds well to the difficult to handle scenario of a spatially quiescent image suddenly transitioning to a spatially rich image. Even in the face of such difficult scenarios, the system detects and removes residual echo from the microphone signal, instead of allowing the undesired residual echo to pass through.

Spatial quiescence protection for multi-channel acoustic echo cancellation

A beamforming technique for a microphone array is described to attenuate a source of undesired noise that is deemed the most limiting to audio quality in an acoustic environment. Possible sources of undesired noise include echo, background noise (stationary) and other interference signals (non-stationary). The beamforming technique is updated based on long-term evaluations. Once an evaluation occurs and a decision is made, the beamformer adapts with a maximum responsiveness and without intentional delay, and therefore not affecting the beamformer's tracking ability. When fixed beamforming is utilized, one of several fixed beamformers having different attenuation targets are selected to implement noise attenuation. When adaptive beamforming is utilized, the beamformer adapts whenever the selected target is deemed dominant.

Beamforming apparatus and method based on long-term properties of sources of undesired noise affecting voice quality

Systems and methods are described that perform audio source localization in a manner that provides increased robustness and responsiveness in the presence of acoustic echo. The systems and methods calculate a difference between a signal level associated with one or more of the audio signals generated by a microphone array and an estimated level of acoustic echo associated with one or more of the audio signals. This information is then used to determine whether and/or how to perform audio source localization. For example, a controller may use the difference to determine whether or not to freeze an audio source localization module that operates on the audio signals. As another example, the audio source localization module may incorporate the difference (or the estimated level of acoustic echo used to calculate the difference) into the logic that is used to determine the location of a desired audio source.

Audio source localization system and method

A system and method that automatically disables and/or enables an acoustic beamformer is described herein. The system and method automatically generates an output audio signal by applying beamforming to a plurality of audio signals produced by an array of microphones when it is determined that such beamforming is working effectively and generates the output audio signal based on an audio signal produced by a designated microphone within the array of microphones when it is determined that the beamforming is not working effectively. Depending upon the implementation, the determination of whether the beamforming is working effectively may be based upon a measure of distortion associated with the beamformer response, an estimated level of reverberation, and/or the rate at which a computed look direction used to control the beamformer changes.

System and method for automatic disabling and enabling of an acoustic beamformer

During playing of a streamed audio while engaging in a voice communication session, a communication device may be operable to generate a background audio during an echo cancellation operation for the voice communication session, using known information associated with the streamed audio. The streamed audio may comprise audio content that is received from one or more external sources and/or locally generated within the communication device. The known information associated with the streamed audio may comprise an echo replica corresponding to an echo associated with the streamed audio and/or a modified version of the streamed audio. In instances when a residual echo suppression is operational during the echo cancellation operation, the communication device may be operable to suppress a residual echo based on a signal level of the echo replica corresponding to the echo associated with the streamed audio and/or a signal level of the modified version of the streamed audio.

Method and system for echo cancellation in presence of streamed audio

A system and method for performing audio source localization that uses minimum variance distortionless response (MVDR) beams or other super-directive beams that are more suitable for reducing noise, interference and/or acoustic coupling than the delay-and-sum beams conventionally used in performing audio source localization based on a Steered Response Power (SRP) approach. Since super-directive beams such as MVDR beams do not provide good properties for performing conventional SRP-based audio source localization, an embodiment of the present invention utilizes a different metric than maximum response power in order to determine which of a plurality of beams provides the best response for audio source localization. This metric involves identifying which beam provides the smallest measure of distortion with respect to a reference power or reference response.

An audio/video (A/V) capture device and method that capture audio and video in a spatially synchronized manner. In one implementation, the device and method automatically adjust the shape of a spatial directivity pattern of a microphone array used for acquiring audio so that the pattern is spatially synchronized with an amount of video zoom being applied by a video acquisition section to acquire video. For example, a wider spatial directivity pattern may automatically be used during wide-angle shots and a narrower spatial directivity pattern may automatically be used during close-ups. This beneficially allows for the consistent attenuation of audio signals received from audio sources that lie outside the field of view of the video acquisition section while passing or even enhancing audio signals received from audio sources that lie within the field of view even though the width of the field of view has changed.

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Franck Beaucoup