Abstract: Partially adaptive audio beamforming systems and methods are provided that enable improved acoustic echo cancellation of sound played on a loudspeaker that is in close proximity to a microphone array in an audio device. A stored beamformer parameter, such as an inverse covariance matrix, can be utilized by a frequency domain beamformer to generate a beamformed signal. The overall performance and resource usage by the audio device can be optimized.

Abstract: A scalable conferencing system can include a set of conferencing devices configured to be placed on a surface (such as, a table), mounted on a ceiling, or attached to a wall. The conferencing devices can be configured to be positioned in a room and pick up and/or reproduce audio in the room. Depending on the configuration and/or characteristics of the room (such as, dimensions, geometry, acoustical properties, furnishings, or the like), a plurality of conferencing devices of a particular type can be deployed in the room and/or conferencing devices of another particular type may not be deployed. The conferencing system can be used for audio and/or video conferencing.

Abstract: A method for real-time monitoring of audio signals reception quality includes receiving output signals from a plurality of microphone clusters, each microphone cluster having at least two microphone units to receive audio signals from at least two distinct directions and output corresponding electrical signals; identifying comparative features of output signals for each of the microphone clusters; and selecting at least one microphone cluster based on the identified features. A system for real-time monitoring of audio signals reception quality includes a plurality of microphone clusters, each microphone cluster having at least two microphone units to receive audio signals from at least two distinct directions and output corresponding electrical signals; and a main audio unit to identify comparative features of output signals for each of the microphone clusters and to select at least one microphone cluster based on the identified features.

Abstract: A method for real-time monitoring of audio signals reception quality includes receiving output signals from a plurality of microphone clusters, each microphone cluster having at least two microphone units to receive audio signals from at least two distinct directions and output corresponding electrical signals; identifying comparative features of output signals for each of the microphone clusters; and selecting at least one microphone cluster based on the identified features. A system for real-time monitoring of audio signals reception quality includes a plurality of microphone clusters, each microphone cluster having at least two microphone units to receive audio signals from at least two distinct directions and output corresponding electrical signals; and a main audio unit to identify comparative features of output signals for each of the microphone clusters and to select at least one microphone cluster based on the identified features.

Abstract: A sensor array receiving system which incorporates one or more filters that are capable of adaptive and/or fixed operation. The filters are defined by a multiple of coefficients and the coefficients are set so as to maximize the signal to noise ratio of the receiving array's output. In one preferred embodiment, the filter coefficients are adaptively determined and are faded into a predetermined group of fixed values upon the occurrence of a specified event. Thereby, allowing the sensor array to operate in both the adaptive and fixed modes, and providing the array with the ability to employ the mode most favorable for a given operating environment. In another preferred embodiment, the filter coefficients are set to a fixed group of values which are determined to be optimal for a predefined noise environment.

Abstract: A noise canceling method and apparatus for canceling noise by time domain processing sub-bands of a digital input signal. The input signal is divided into a number of frequency-limited time-domain sub-bands. Each sub-band is then individually processed to cancel noise present in the signal. The noise processing includes exponential averaging of the input, noise estimation, and subtraction processing. The noise subtraction process is simplified by generating a filter coefficient that is exponentially smoothed, hard limited, and multiplied with the input signal to generate the noise processed output for each sub-band. The noise processed bands are then recombined into a digital output signal. Implementation may be effected in software or hardware and applied to various noise canceling and signal processing applications.

Abstract: A threshold detector precisely detects the positions of the noise elements, even within continuous speech segments, by determining whether frequency spectrum elements, or bins, of the input signal are within a threshold set according to current and future minimum values of the frequency spectrum elements. In addition, the threshold is continuously set and initiated within a predetermined period of time. The estimate magnitude of the input audio signal is obtained using a multiplying combination of the real and imaginary part of the input in accordance with the higher and lower values between the real and imaginary part of the signal. In order to further reduce instability of the spectral estimation, a two-dimensional smoothing is applied to the signal estimate using neighboring frequency bins and an exponential average over time. A filter multiplication effects the subtraction thereby avoiding phase calculation difficulties and effecting full-wave rectification which further reduces artifacts.

Abstract: Interference canceling is provided for canceling, from a target signal generated from a target source, an interference signal generated by an interference source. The beam splitter beam-splits the target signal into a plurality of band-limited target signals band-limited frequency bands and beam-splits the interference signal into corresponding band-limited frequency bands. The adaptive filter adaptively filters each band-limited interference signal from each corresponding band-limited target signal. The inhibitor can permit the adaptive filter to adapt or change coefficients when a signal-to-noise ratio of the reference signal exceeds a predetermined threshold, to be determined periodically, over a signal-to-noise ratio of the main signal. The beam selector selects at least one of a plurality of beams for adaptive filtering by the adaptive filter representing a direction from which the main signal is received.