Abstract: A system and method for processing an audio input signal includes a microphone, a controller, and a communication link that may be coupled to a remote speaker. The microphone captures the audio input signal and communicates the audio input signal to the controller, and the controller is coupled to the communication link. The controller includes executable code to generate, via a linear noise reduction filtering algorithm, a first resultant based upon the audio input signal, and generate, via non-linear post filtering algorithm, a second resultant based upon the first resultant. An audio output signal is generated based upon the second resultant employing a feature restoration algorithm. The audio output signal is communicated, via the communication link, to a speaker that may be at a remote location.

Abstract: A system and method for processing an audio input signal includes a microphone, a controller, and a communication link that may be coupled to a remote speaker. The microphone captures the audio input signal and communicates the audio input signal to the controller, and the controller is coupled to the communication link. The controller includes executable code to generate, via a linear noise reduction filtering algorithm, a first resultant based upon the audio input signal, and generate, via non-linear post filtering algorithm, a second resultant based upon the first resultant. An audio output signal is generated based upon the second resultant employing a feature restoration algorithm. The audio output signal is communicated, via the communication link, to a speaker that may be at a remote location.

Abstract: An audio system includes: a speaker; a microphone that generates a microphone signal based on sound output from the speaker; a mixer module configured to generate a mixed signal by mixing the microphone signal with an audio signal; a filter module configured to filter the mixed signal to produce a filtered signal and to apply the filtered signal to the speaker; and a detector module configured to determine a howling frequency in the microphone signal attributable to sound output from the speaker, where the filter module is configured to decrease a magnitude of the filtered signal at the howling frequency.

Abstract: An audio system includes: a speaker; a microphone that generates a microphone signal based on sound output from the speaker; a mixer module configured to generate a mixed signal by mixing the microphone signal with an audio signal; a filter module configured to filter the mixed signal to produce a filtered signal and to apply the filtered signal to the speaker; and a detector module configured to determine a howling frequency in the microphone signal attributable to sound output from the speaker, where the filter module is configured to decrease a magnitude of the filtered signal at the howling frequency.

Abstract: The present application relates to a system and method for providing autoregressive based residual echo suppression in the STFT domain in a bidirectional vehicle communications system including receiving, from a communications processor, a speaker signal for coupling to a speaker, receiving, from a microphone, a microphone signal wherein the microphone signal includes a voice signal and a residual echo signal, transforming the signals to the STFT domain generating an estimated power spectral density of the residual echo signal in response to a prior power spectral density of a prior residual echo signal, isolating the voice signal from the microphone signal by multiplying the estimated residual echo gain generated using the estimated power spectral density of the residual echo signal with the microphone signal, transforming the signals back to the time domain and coupling the voice signal to the communications processor.

Abstract: The present application relates to a system and method for receiving, via a microphone array, an incoming acoustic signal including a desired signal and an undesired signal, performing a first minimum variance distortionless response beamforming operation on the incoming acoustic signal to isolate the desired signal, performing a second minimum variance distortionless response beamforming operation, by the signal processor, on the incoming acoust signal to isolate the undesired signal, filtering the desired signal to generate a filtered desired signal, combining an inverse of the filtered desired signal with the undesired signal to generate a combined undesired signal, filtering the combined undesired signal to generate a filtered combined undesired signal, combining an inverse of the combined undesired signal and the desired signal to generate an output signal, and generating a data signal in response to the output signal for transmission via a wireless network.

Abstract: The present application relates to a system and method for receiving, via a microphone array, an incoming acoustic signal including a desired signal and an undesired signal, performing a first minimum variance distortionless response beamforming operation on the incoming acoustic signal to isolate the desired signal, performing a second minimum variance distortionless response beamforming operation, by the signal processor, on the incoming acoust signal to isolate the undesired signal, filtering the desired signal to generate a filtered desired signal, combining an inverse of the filtered desired signal with the undesired signal to generate a combined undesired signal, filtering the combined undesired signal to generate a filtered combined undesired signal, combining an inverse of the combined undesired signal and the desired signal to generate an output signal, and generating a data signal in response to the output signal for transmission via a wireless network.

Abstract: The present application relates to a system and method for providing autoregressive based residual echo suppression in the STFT domain in a bidirectional vehicle communications system including receiving, from a communications processor, a speaker signal for coupling to a speaker, receiving, from a microphone, a microphone signal wherein the microphone signal includes a voice signal and a residual echo signal, transforming the signals to the STFT domain generating an estimated power spectral density of the residual echo signal in response to a prior power spectral density of a prior residual echo signal, isolating the voice signal from the microphone signal by multiplying the estimated residual echo gain generated using the estimated power spectral density of the residual echo signal with the microphone signal, transforming the signals back to the time domain and coupling the voice signal to the communications processor.

Abstract: Techniques are provided for reduction of echo in a received audio signal based on infinite impulse response (IIR) acoustic echo cancellation in the frequency domain. A methodology implementing the techniques according to an embodiment includes estimating an echo path transfer function associated with the received audio signal. The received audio signal includes a combination of a speech signal and a reference signal modified by the echo path transfer function. The estimation employs an IIR filter and a finite impulse response (FIR) filter, both of which operate in the frequency domain. The IIR filter is configured to model longer term echo components and the FIR filter is configured to model shorter term echo components. The method further includes applying the filters to the reference signal to generate an echo correction signal which is subtracted from the received audio signal to reduce the echo and generate an estimate of the speech signal.

Abstract: Techniques are provided for reduction of echo in a received audio signal based on infinite impulse response (IIR) acoustic echo cancellation in the frequency domain. A methodology implementing the techniques according to an embodiment includes estimating an echo path transfer function associated with the received audio signal. The received audio signal includes a combination of a speech signal and a reference signal modified by the echo path transfer function. The estimation employs an IIR filter and a finite impulse response (FIR) filter, both of which operate in the frequency domain. The IIR filter is configured to model longer term echo components and the FIR filter is configured to model shorter term echo components. The method further includes applying the filters to the reference signal to generate an echo correction signal which is subtracted from the received audio signal to reduce the echo and generate an estimate of the speech signal.

Abstract: A method and adaptive processor for estimating a reference signal, comprising receiving or determining a number of groups and respective group sizes, each group associated with a range of delay values of the reference signal, determining a multiplicity of coefficients, each coefficient associated with a specific delay of the reference signal, determining a multiplicity of weights, each weight associated with one of the groups, multiplying each sample of the reference signal having a delay by a corresponding coefficient to obtain a first product, and summing a multiplicity of first products associated with a group into a group sum signal sample, and multiplying each group sum by a weight associated with the group to obtain a second product, and summing all second products to obtain an estimated signal value.

Abstract: A method and apparatus for filtering a reference signal by a series of taps having coefficients, comprising dividing the taps into at least one layer of a plurality of groups, each group comprising a plurality of taps, as a first layer, forming a plurality of coefficients arranged in at least one group, as at least one subsequent layer and forwarding multiply-accumulate results of each group in each layer sequentially to the at least one group in the at least one subsequent layer to generate an output signal, and adjusting the coefficients based on an error signal formed as a difference between the output signal and a received input signal related to the reference signal and an interim error signal as a difference between the input signal and a summation of the multiply-accumulate results of at least one layer.