Abstract: A noise-cancellation system includes a noise-cancellation filter in communication with at least one speaker, the noise-cancellation filter generating a noise-cancellation signal that, when actuated by the at least one speaker, cancels noise within at least one cancellation zone; and an amplifier disposed between the noise-cancellation filter and the speaker, the amplifier applying a first scaling gain to the noise-cancellation signal and outputting an scaled noise-cancellation signal, the scaled noise-cancellation signal being a linear reduction of the noise-cancellation signal when the first scaling gain is less than unity, wherein the first scaling gain is set to less than unity in response to a signal representative of the noise-cancellation signal exceeding a threshold.

Abstract: A system for capturing a user's voice, including a plurality of microphones disposed about a vehicle cabin, each of the plurality of microphones generating a microphone signal, wherein the vehicle cabin defines a plurality of seating positions; a voice-activity detector configured to detect when, at least, a user seated in a target seat of the plurality of seating positions is speaking; and an adaptive beamformer configured to receive the microphone signals from the plurality of microphones and to generate, based on the microphone signals and a noise coherence matrix, an estimate of the acoustic signal at the target seating position, according to an adaptive beamforming algorithm, wherein the noise coherence matrix ceases to be updated when, according to the voice-activity detector, the user seated in the target seating position is speaking.

Abstract: Methods, systems, and computer-readable media are provided for detecting voice activity. A primary signal is configured to include a speech component representative of a user's speech when the user is speaking in a detection region, or environment. A reference signal is configured to include a reduced speech component relative to the primary signal. One or more conditions of the detection region is/are detected, and a threshold value is selected (or, optionally, calculated) based upon the detected condition(s). The primary signal is compared to the reference signal, with respect to the selected threshold value. An indication of whether the user is speaking is selectively output, based at least in part upon the comparison.

Abstract: A system for capturing a user's voice, including a plurality of microphones disposed about a vehicle cabin, each of the plurality of microphones generating a microphone signal, wherein the vehicle cabin defines a plurality of seating positions; a voice-activity detector configured to detect when, at least, a user seated in a target seat of the plurality of seating positions is speaking; and an adaptive beamformer configured to receive the microphone signals from the plurality of microphones and to generate, based on the microphone signals and a noise coherence matrix, an estimate of the acoustic signal at the target seating position, according to an adaptive beamforming algorithm, wherein the noise coherence matrix ceases to be updated when, according to the voice-activity detector, the user seated in the target seating position is speaking.

Abstract: A method for preparing reference signals for an echo cancellation system disposed in a vehicle, comprising the steps of: receiving a plurality of drive signals, each drive signal being provided to an associated transducer of a plurality of acoustic transducers such that the associated acoustic transducer transduces the drive signal into an acoustic signal, filtering each drive signal with a respective filter of a plurality of filters to produce a plurality of filtered signals, wherein each of the plurality of filters approximates a transfer function from an associated acoustic transducer to a microphone disposed within the vehicle such that the plurality of filtered signals each estimate a respective acoustic signal at the microphone; summing together at least a subset of the plurality of filtered signals to produce a summed reference signal; and outputting the summed reference signal to an echo cancellation system.

Abstract: A method for preparing reference signals for an echo cancellation system disposed in a vehicle, comprising the steps of: receiving a plurality of drive signals, each drive signal being provided to an associated transducer of a plurality of acoustic transducers such that the associated acoustic transducer transduces the drive signal into an acoustic signal, filtering each drive signal with a respective filter of a plurality of filters to produce a plurality of filtered signals, wherein each of the plurality of filters approximates a transfer function from an associated acoustic transducer to a microphone disposed within the vehicle such that the plurality of filtered signals each estimate a respective acoustic signal at the microphone; summing together at least a subset of the plurality of filtered signals to produce a summed reference signal; and outputting the summed reference signal to an echo cancellation system.

Abstract: A computer-implemented method for determining whether the noise floor of a sensor is deviated from an expected value, comprising the steps of: receiving a sensor signal from a sensor; determining a plurality of power spectral densities from a plurality of successive frames of samples of the sensor signal, each of the plurality of power spectral densities being determined from a respective frame of the plurality of successive frames, each power spectral density being comprised of a plurality of frequency bins, each frequency bin being associated with a power of the respective frame at the frequency of the respective frequency bin, wherein each successive frame of the plurality of successive frames differs by at least one sample; identifying a minimum power of the plurality of power spectral densities; and determining whether the minimum power exceeds a threshold value.

Abstract: A system for capturing a user's voice, including a plurality of microphones disposed about a vehicle cabin, each of the plurality of microphones generating a microphone signal, wherein the vehicle cabin defines a plurality of seating positions; a voice-activity detector configured to detect when, at least, a user seated in a target seat of the plurality of seating positions is speaking; and an adaptive beamformer configured to receive the microphone signals from the plurality of microphones and to generate, based on the microphone signals and a noise coherence matrix, an estimate of the acoustic signal at the target seating position, according to an adaptive beamforming algorithm, wherein the noise coherence matrix ceases to be updated when, according to the voice-activity detector, the user seated in the target seating position is speaking.

Abstract: In an audio system with a plurality of input signals, the input signals are prioritized from least important to most important. The level of the aggregate of all of the input signals is compared to a threshold level. If the level is greater than the threshold, the levels of one or more of the input signals are reduced one at a time, in order from the least important input signal to the most important input signal.

Abstract: A vehicle-implemented noise-cancellation system, includes: a noise-cancellation system disposed in a vehicle, the noise-cancellation system comprising an adaptive filter being adjusted according to a reference signal and an error signal, the adaptive filter outputting a noise-cancellation signal, which, when transduced into a noise-cancellation audio signal by a speaker, cancels road noise within at least one zone within a cabin of the vehicle; and an adjustment module configured to vary a power of the noise-cancellation signal or a rate of adaptation of the adaptive filter from a first value to a second value, passing through at least one intermediate value between the first value and the second value, based on a time-varying signal indicative of a signal-to-noise ratio of the reference signal with respect to a first criterion.

Abstract: Audio systems, methods, and computer readable media for managing audio headroom are provided. At least two input signals are received and combined. The combined signals is compared to a threshold value and may be adjusted if the combined signal exceeds the threshold value. A gain is applied to the first input signal based upon the combined signal being above the threshold value. The gain may be an attenuating gain. Accordingly, a gain is applied to at least one input signal to reduce the input signal when a combination of the input signals exceeds a threshold value.

Abstract: A method includes receiving a set of time domain samples representing audio captured using one or more microphones, and generating, from the time domain samples, a spectrum comprising a set of frequency domain coefficients, each coefficient representing a frequency bin corresponding to a range of frequencies. The method also includes adjusting the spectrum to generate a smoothed spectrum, wherein generating the smoothed spectrum includes determining that a magnitude of a first frequency domain coefficient is less than a threshold, and in response, replacing the first frequency domain coefficient by a value computed as a function of a plurality of frequency domain coefficients that include the first frequency domain coefficient. The method further includes generating an audio signal based on time domain samples computed using the smoothed spectrum.

Abstract: A noise-cancellation system includes a noise-cancellation filter in communication with at least one speaker, the noise-cancellation filter generating a noise-cancellation signal that, when actuated by the at least one speaker, cancels noise within at least one cancellation zone; and an amplifier disposed between the noise-cancellation filter and the speaker, the amplifier applying a first scaling gain to the noise-cancellation signal and outputting an scaled noise-cancellation signal, the scaled noise-cancellation signal being a linear reduction of the noise-cancellation signal when the first scaling gain is less than unity, wherein the first scaling gain is set to less than unity in response to a signal representative of the noise-cancellation signal exceeding a threshold.

Abstract: In an audio system with a plurality of input signals, the input signals are prioritized from least important to most important. The level of the aggregate of all of the input signals is compared to a threshold level. If the level is greater than the threshold, the levels of one or more of the input signals are reduced one at a time, in order from the least important input signal to the most important input signal.

Abstract: A method includes receiving multiple samples of time-domain data that includes noise, computing a first two-dimensional (2D) time-frequency representation of the time domain data, and processing the first time-frequency representation using a time-frequency noise reduction mask to generate a second, noise-reduced time-frequency representation of the time domain data. The method also includes generating a time domain output based on the noise-reduced time-frequency representation.

Abstract: A system for capturing a user's voice, including a plurality of microphones disposed about a vehicle cabin, each of the plurality of microphones generating a microphone signal, wherein the vehicle cabin defines a plurality of seating positions; a voice-activity detector configured to detect when, at least, a user seated in a target seat of the plurality of seating positions is speaking; and an adaptive beamformer configured to receive the microphone signals from the plurality of microphones and to generate, based on the microphone signals and a noise coherence matrix, an estimate of the acoustic signal at the target seating position, according to an adaptive beamforming algorithm, wherein the noise coherence matrix ceases to be updated when, according to the voice-activity detector, the user seated in the target seating position is speaking.

Abstract: A method includes receiving multiple frames of time-domain data that includes noise, and computing, for a first frame of the multiple frames, a frequency domain value for each of multiple frequency bins, each frequency bin representing a corresponding range of frequencies. The method also includes determining that a first frequency domain value corresponding to a first frequency bin is less than or equal to a first threshold value, and in response, updating the first frequency domain value based on a function of (i) a smoothing parameter, and (ii) a second frequency domain value corresponding to the first frequency bin. The second frequency domain value is computed using one or more preceding frames of the multiple frames. The method further includes determining a noise floor corresponding to the first frequency bin using the updated first frequency domain value.

Abstract: A method includes receiving multiple samples of time-domain data that includes noise, computing a first two-dimensional (2D) time-frequency representation of the time domain data, and processing the first time-frequency representation using a time-frequency noise reduction mask to generate a second, noise-reduced time-frequency representation of the time domain data. The method also includes generating a time domain output based on the noise-reduced time-frequency representation.

Abstract: A vehicle-implemented noise-cancellation system, includes: a noise-cancellation system disposed in a vehicle, the noise-cancellation system comprising an adaptive filter being adjusted according to a reference signal and an error signal, the adaptive filter outputting a noise-cancellation signal, which, when transduced into a noise-cancellation audio signal by a speaker, cancels road noise within at least one zone within a cabin of the vehicle; and an adjustment module configured to vary a power of the noise-cancellation signal or a rate of adaptation of the adaptive filter from a first value to a second value, passing through at least one intermediate value between the first value and the second value, based on a time-varying signal indicative of a signal-to-noise ratio of the reference signal with respect to a first criterion.

Abstract: A computer-implemented method for determining whether the noise floor of a sensor is deviated from an expected value, comprising the steps of: receiving a sensor signal from a sensor; determining a plurality of power spectral densities from a plurality of successive frames of samples of the sensor signal, each of the plurality of power spectral densities being determined from a respective frame of the plurality of successive frames, each power spectral density being comprised of a plurality of frequency bins, each frequency bin being associated with a power of the respective frame at the frequency of the respective frequency bin, wherein each successive frame of the plurality of successive frames differs by at least one sample; identifying a minimum power of the plurality of power spectral densities; and determining whether the minimum power exceeds a threshold value.