Various implementations include a method for implementing a computational architecture for a personal active noise reduction (ANR) device. A method includes receiving a source audio stream with a first DSP and performing ANR on the source audio stream utilizing operational parameters stored in the first DSP; outputting a processed audio stream from the first DSP; generating state data with a second DSP in response to an analysis of at least one of the source audio stream, microphone inputs and the processed audio stream, and communicating signals to the first DSP over a common bus coupled to the first and second DSPs to alter the operational parameters in the first DSP; and utilizing a general purpose processor coupled to both the first DSP and the second DSP to communicate control signals with a communication interface, process state data from the second DSP, and alter the operational parameters in the first DSP.

An active noise reduction device includes: a reference signal input terminal that receives a reference signal from a reference signal source attached to an automobile; a simulated vibration transfer characteristics filter unit that generates a second signal by correcting, using simulated vibration transfer characteristics, a first signal for outputting, from a loudspeaker attached to the automobile, a sound different from a canceling sound, the simulated vibration transfer characteristics simulating vibration transfer characteristics from the loudspeaker to the reference signal source; a first subtracter that outputs a corrected reference signal obtained by subtracting the second signal generated, from the reference signal received by the reference signal input terminal; and an adaptive filter unit that applies an adaptive filter to the corrected reference signal outputted from the first subtracter to generate a canceling signal to be used to output the canceling sound.

An audio system for an ear mountable playback device includes a speaker, an error microphone, which senses sound being output from the speaker, and a sound control processor. The processor is configured for controlling and/or monitoring a playback of a detection signal or a filtered version of the detection signal via the speaker, recording an error signal from the error microphone, and determining whether the playback device is in a first state, where the playback device is worn by a user, or in a second state, where the playback device is not worn by a user, based on processing of the error signal.

A noise controlling method, comprising: generating one reference signal representing a primary noise; generating one secondary noise in response to a control signal, for cancelling the primary noise; generating one error signal representing a superposition of the primary noise and the secondary noise at a position. The method further comprises: generating at least one additional reference signal, and/or at least one additional secondary noise, and/or at least one additional error signal; and generating the control signal(s) for generating the secondary noise(s), by executing an adaptive subband filtering algorithm based on the reference signal(s) and the error signal(s); wherein the step of generating the control signal(s) comprises: decomposing the reference signal(s) and the error signal(s) into subband reference signal(s) and subband error signal(s), respectively, for each subband of a plurality of subbands; updating a subset of one or more subband adaptive filters for at least one subband of the plurality of subbands, based on a subset of the subband reference signal(s) of the at least one subband and a subset of the subband error signal(s) of the at least one subband, wherein at least one of said three subsets is a proper subset; updating at least one fullband adaptive filter based on the updated subband adaptive filter(s); generating the control signal(s) by filtering the reference signal(s) by the updated at least one fullband adaptive filter.

Various implementations include a computational architecture for a personal active noise reduction (ANR) device. The device includes a communication interface that receives an audio stream, a driver, a microphone system and an ANR processing platform. The platform includes a first DSP configured to: receive the audio stream and signals from the microphone system, perform ANR on the audio stream according to a set of parameters in the first DSP, and output a processed audio stream. The platform includes a second DSP configured to: generate state data in response to an analysis of the source audio stream, signals from the microphone system, and the processed audio stream; and alter the operational parameters on the first DSP. The platform includes a general purpose processor configured to: communicate control signals with the communication interface, process state data from the second DSP, and alter the parameters on the first DSP.

A noise cancellation circuit includes: a first filter circuit for filtering a first input signal according to a first filter coefficient to generate a first filtered signal; a signal processing circuit for generating a feedback signal according to a second input signal and an audio signal; a second filter circuit for filtering the feedback signal according to a second filter coefficient to generate a second filtered signal; a first multiplication circuit for multiplying the first filtered signal by a first scale to generate a first intermediate signal; a second multiplication circuit for multiplying the second filtered signal by a second scale to generate a second intermediate signal; a first adder circuit for adding the first intermediate signal to the second intermediate signal to generate a noise cancellation signal; and a second adder circuit for adding the noise cancellation signal to the audio signal to generate an output signal.

A method for hybrid noise suppression involves receiving a first processed audio signal and a second processed audio signal from an audio device. The first processed audio signal results from a comprehensive audio processing including a noise spectrum estimate-based noise suppression performed on a noisy audio input signal obtained by the audio device. The second processed signal results from a partial audio processing excluding the noise spectrum estimate-based noise suppression performed on the noisy audio input signal. The method further involves temporally aligning the second processed audio signal with the first processed audio signal, predicting a noise suppression parameter using a neural network model operating on the second processed audio signal after the temporal alignment, generating a noise-suppressed audio output signal from the first processed audio signal after the temporal alignment using the noise suppression parameter, and outputting the noise-suppressed audio output signal.

Systems and methods include a digital control module that receives and processes audio data for output through a loudspeaker. An analog block receives the audio data and the power control signal and amplifies the audio data for output. A first processing path includes a buffer to delay the audio data, a first component to combine the buffered audio data and anti-noise. A second processing path includes an absolute value block to receive the audio data and an envelope detector to receive the absolute value data and generate a maximum value for the envelope. An anti-noise path includes an absolute value block configured to determine an anti-noise absolute value which is combined with the absolute value anti-noise data. A power generator receives the output from the envelope detector and updates a power level to approximate a minimum powered needed to process the audio signal.

With respect to a noise reduction device using a speaker and a microphone corresponding to each seat in a vehicle to reduce a noise in each seat, the noise reduction device includes, a signal processing unit configured to generate a canceling sound that reduces a noise at an ear of an occupant in a predetermined seat by using an auxiliary filter, an operation setting unit configured to disable operations of a speaker and a microphone corresponding to each empty seat in the vehicle, and an auxiliary filter setting unit configured to change a setting value of the auxiliary filter used by the signal processing unit to generate the canceling sound in accordance with the number of occupants in seats other than the predetermined seat, the seats affecting the noise in the predetermined seat.

An adaptive active noise cancellation apparatus performs a filtering operation in a first digital domain and performs adaptation of the filtering operation in a second digital domain.