Abstract: A wind noise suppression system may include a local wind noise suppression block, a receiver, and a wind noise suppression fusion block. The local wind noise suppression block may be configured to analyze an audio signal and generate, based on the audio signal, local wind noise information associated with a first device comprising the wind noise suppression system, wherein the local wind noise information includes parameters for suppressing local wind noise at the first device. The receiver may be configured to receive remote wind noise information associated with a second device, wherein the remote wind noise information includes parameters for suppressing remote wind noise at the second device. The wind noise suppression fusion block may be configured to combine the local wind noise information and the remote wind noise information into fused wind noise information and apply parameters of the fused wind noise information to modify audio information for playback to an audio transducer of the first device.

Abstract: An adaptive beamformer includes at least first and second microphones that generate respective audio signals that include speech and noise, a controller that detects occurrences of speech and noise within the audio signals, an adaptive speech cancelling filter that cancels speech from the audio signal of the second microphone to provide a speech-cancelled signal, an adaptive mixing block that combines the speech-cancelled signal and the second microphone audio signal to provide a noise reference signal in a weighted manner such that a weight of the second microphone signal is increased proportionally with an amount of the detected noise and a weight of the speech-cancelled signal is increased proportionally with an amount of the detected speech, and an adaptive noise cancelling filter that uses the noise reference signal to remove the noise from the first microphone audio signal.

Abstract: An adaptive beamformer includes at least first and second microphones that generate respective audio signals that include speech and noise, a controller that detects occurrences of speech and noise within the audio signals, an adaptive speech cancelling filter that cancels speech from the audio signal of the second microphone to provide a speech-cancelled signal, an adaptive mixing block that combines the speech-cancelled signal and the second microphone audio signal to provide a noise reference signal in a weighted manner such that a weight of the second microphone signal is increased proportionally with an amount of the detected noise and a weight of the speech-cancelled signal is increased proportionally with an amount of the detected speech, and an adaptive noise cancelling filter that uses the noise reference signal to remove the noise from the first microphone audio signal.

Abstract: An apparatus includes a beamformer, an echo suppression control unit, and a residual echo cancellation unit. The beamformer is configured to pass desired portions of audio signals and to suppress undesired portions of the audio signals. The beamformer includes a speech blocking filter to prevent suppression of near-end desired talker speech in the audio signals and an echo suppression filter to suppress echo in the audio signals. An echo suppression control unit is coupled to the beamformer and receives signals and determines whether to dynamically adapt the speech blocking filter or to dynamically adapt the echo suppression filter. The speech blocking filter remains unchanged during dynamic adaptation of the echo suppression filter, and the echo suppression filter remains unchanged during dynamic adaptation of the speech blocking filter. The residual echo cancellation unit is coupled to the beamformer and receives output audio signals from the beamformer and further suppresses residual echo.

Abstract: An apparatus includes a beamformer, an echo suppression control unit, and a residual echo cancellation unit. The beamformer is configured to pass desired portions of audio signals and to suppress undesired portions of the audio signals. The beamformer includes a speech blocking filter to prevent suppression of near-end desired talker speech in the audio signals and an echo suppression filter to suppress echo in the audio signals. An echo suppression control unit is coupled to the beamformer and receives signals and determines whether to dynamically adapt the speech blocking filter or to dynamically adapt the echo suppression filter. The speech blocking filter remains unchanged during dynamic adaptation of the echo suppression filter, and the echo suppression filter remains unchanged during dynamic adaptation of the speech blocking filter. The residual echo cancellation unit is coupled to the beamformer and receives output audio signals from the beamformer and further suppresses residual echo.

Abstract: Acoustic echo cancellation (AEC) processing may be improved by performing echo cancellation using a combined multi-channel reference signal. Two or more reference signals, such as a left and right channel of a stereo source, may be combined and provided to an AEC block configured to receive the combined signal and perform AEC processing using the combined signal. The AEC block may include an adaptive filter that performs operations that cause pre-whitening of the combined reference signal and de-correlation of the individual channels within the combined reference signal. The pre-whitening of the signal flattens the spectrum of the combined reference signal, which may improve convergence speed of the AEC processing in cancelling the echo. The de-correlating of the signal cancels inter-channel correlation between the multiple channels, which may improve convergence speed of the AEC processing in cancelling the echo.

Abstract: A telephone includes a transmit channel and a receive channel, each including a bank of sub-band filters having a VAD coupled one to each sub-band filter. Each VAD measures the spectral energy in a sub-band, compares the spectral energy to a first threshold, and produces an output signal representative of whether or not the first threshold is exceeded. The voice activity detector also includes a threshold circuit for calculating a dynamically adjustable noise threshold based upon averaged measured spectral energy. A wide band or system VAD monitors echo canceling circuitry to detect voice activity and double talk.

Abstract: A telephone includes a transmit channel and a receive channel, each including a bank of sub-band filters having a VAD coupled one to each sub-band filter. Each VAD measures the spectral energy in a sub-band, compares the spectral energy to a first threshold, and produces an output signal representative of whether or not the first threshold is exceeded. The voice activity detector also includes a threshold circuit for calculating a dynamically adjustable noise threshold based upon averaged measured spectral energy. A wide band or system VAD monitors echo canceling circuitry to detect voice activity and double talk.

Abstract: A background noise estimate based upon a modified Doblinger noise estimate is used for modulating the output of a pseudo-random phase spectrum generator to produce the comfort noise. The circuit for estimating noise includes a smoothing filter having a slower time constant for updating the noise estimate during noise than during speech. Comfort noise is smoothly inserted by basing the amount of comfort noise on the amount of noise suppression. A discrete inverse Fourier transform converts the comfort noise back to the time domain and overlapping windows eliminate artifacts that may have been produced during processing.

Abstract: Voice activity is detected by comparing a signal with two thresholds and producing data representing the energy of the signal. The data, in binary form, is compared with thresholds to determine voice activity. In accordance with another aspect of the invention, the thresholds are adjusted based upon statistical information. In accordance with another aspect of the invention, the data can be weighted to provide an indication of the quasi-RMS energy of an input signal.

Abstract: Voice activity is detected by comparing an analog signal with two voltage thresholds and producing data representing the energy of the signal. The data, in binary form, is compared with thresholds to determine voice activity. In accordance with another aspect of the invention, the thresholds are adjusted based upon statistical information. In accordance with another aspect of the invention, the data can be weighted to provide an indication of the quasi-RMS energy of an input signal. The input signal itself is not converted into digital form yet the data derived from the input signal has high resolution.

Abstract: A telephone includes a transmit channel and a receive channel, each including a bank of sub-band filters having a VAD coupled one to each sub-band filter. Each VAD measures the spectral energy in a sub-band, compares the spectral energy to a first threshold, and produces an output signal representative of whether or not the first threshold is exceeded. The voice activity detector also includes a threshold circuit for calculating a dynamically adjustable noise threshold based upon averaged measured spectral energy. A wide band or system VAD monitors echo canceling circuitry to detect voice activity and double talk.

Abstract: Voice activity is detected by comparing an analog signal with two voltage thresholds and producing data representing the energy of the signal. The data, in binary form, is compared with thresholds to determine voice activity. In accordance with another aspect of the invention, the thresholds are adjusted based upon statistical information. In accordance with another aspect of the invention, the data can be weighted to provide an indication of the quasi-RMS energy of an input signal. The input signal itself is not converted into digital form yet the data derived from the input signal has high resolution.

Abstract: Voice activity is detected by comparing a signal with two thresholds and producing data representing the energy of the signal. The data, in binary form, is compared with thresholds to determine voice activity. In accordance with another aspect of the invention, the thresholds are adjusted based upon statistical information. In accordance with another aspect of the invention, the data can be weighted to provide an indication of the quasi-RMS energy of an input signal.

Abstract: Correlation is improved by comparing the output of a multiplier and low pass filter to a first threshold and incrementing a counter when the output from the filter exceeds the first threshold; comparing the output of the filter to a second threshold and decrementing the counter when the output is below a second threshold. Correlation is indicated by the count in the counter exceeding a predetermined amount.

Abstract: An audio signal is divided into a plurality of bands prior to generating a shadow. The shadow is created by delaying the portion of the audio signal in at least one band by less than fifty milliseconds and combining the shadow signal with the portion of the audio signal. The portions, with any shadows, are combined to produce a reconstructed audio signal. The presence or absence of a shadow signal represents data or the data is represented by two or more shadow signals, in one or more bands. The period of delay of a portion in a band should not equal the period of the center frequency of that band. Preferably, the period of delay of a portion in a band does not equal the period of any frequency within the pass band.

Abstract: The separation of a adjacent band pass filters is improved, without changing the filters, by inverting the output signals from alternate filters and not inverting the remaining output signals. All the output signals are then summed. The result is a deeper notch in the frequency response of adjacent filters.

Abstract: The separation of a adjacent band pass filters is improved, without changing the filters, by inverting the output signals from alternate filters and not inverting the remaining output signals. All the output signals are then summed. The result is a deeper notch in the frequency response of adjacent filters.