An active control method for filtered reference affine projection sign algorithm based on variable step size includes: S1, acquiring impulse noise signals and transmitting the signals to control filters; S2, transmitting the impulse noise signals by the control filters to post filters; S3, generating cancellation signals of the impulse noise signals by the post filters according to the impulse noise signals and internal active control algorithms, and transmitting the cancellation signals to a speaker; S4, sending out the cancellation signal by the speaker to superimpose with the impulse noise signals to cancel the impulse noise signal. A convex combination structure and a variable step size strategy are adopted, and by adjusting step size coefficients in the control filter structure, convergence speed of algorithm is controlled, contradiction between convergence speed and steady-state error is coordinated, convergence performance of control algorithm to impulse noises is improved, and impulse noises are effectively controlled.

An audio device with acoustic echo cancellation includes a device cabinet having a cabinet interior; a first open back driver receiving a first open driver input from an audio source; a second open back driver receiving a second open driver input from the audio source, wherein the first open back driver and the second open back driver are acoustically coupled to the cabinet interior; a reference microphone located in the cabinet interior to record a reference microphone signal based on sound emitted within the cabinet interior by the first open back driver and the second open back driver based on the first open driver input and the second open driver input, respectively; and an acoustic echo cancellation block subtracting a representation of the reference microphone signal from a representation of a set of input microphone signals to provide an echo-cancelled output.

A howling detector is described that is configured to receive an input signal and to determine measure of the linearity of a logarithmic representation of the energy of the input signal. In some examples, this triggers gain adjustment (e.g. of a noise control unit) and, in some further examples, the amount of the gain adjustment may be based on an estimation of the maximum stable gain of a noise control unit.

A noise reduction device includes a processor that converts a noise signal collected by a microphone disposed in a control space into a noise signal in a frequency domain, a storage that stores the converted noise signal in the frequency domain as a reference signal, and a signal generator that generates a noise reduction signal for reducing the noise signal collected by the microphone at a control position of the control space. The processor determines whether or not the noise signal is non-stationary noise based on a frequency characteristic of the converted noise signal in the frequency domain and a frequency characteristic of the reference signal. When it is determined that the noise signal is the non-stationary noise, the processor controls the signal generator so as to cancel generation of the noise reduction signal.

An earpiece (100) and acoustic management module (300) for in-ear canal echo suppression control suitable is provided. The earpiece can include an Ambient Sound Microphone (111) to capture ambient sound, an Ear Canal Receiver (125) to deliver audio content to an ear canal, an Ear Canal Microphone (123) configured to capture internal sound, and a processor (121) to generate a voice activity level (622) and suppress an echo of spoken voice in the electronic internal signal, and mix an electronic ambient signal with an electronic internal signal in a ratio dependent on the voice activity level and a background noise level to produce a mixed signal (323) that is delivered to the ear canal (131).

The disclosure provides an audio processing device comprising a first filter and a second filter. The first filter is configured to generate a first filtered signal based on an error signal, the error signal representative of audible sound at a target space. The second filter is configured to generate a second filtered signal based on the error signal. An anti-noise signal is generated based on the first filtered signal and the second filtered signal, and the anti-noise signal is included in the error signal. The first filter is connected to the second filter in parallel.

A signal processing device according to an embodiment includes: two or more microphones each provided with a sound collection unit directed to an outside of a housing including a driver unit, a control unit (102b) that performs a hearing control of sound output from the driver unit to a listener based on sound signals collected and output by the two or more microphones, and an adjustment unit (200) that adjusts a degree of the hearing control between a degree for wind and a degree for non-wind based on a correlation between the sound signals.

A noise reduction device includes a plurality of noise microphones, noise controller, and control speakers. Noise controller generates a control-sound signal to reduce a noise, at a control center of a control space, with the noise being detected by the plurality of noise microphones. Noise microphone disposed at a shorter distance from the control center than distance “d” indicated by Relational Expression (1) is smaller in number than noise microphones disposed at longer distances than distance “d” where “λ” is a wavelength corresponding to control upper-limit frequency “f” in noise microphones, “d0” is a distance from the control center to control speakers, “t” is a control delay time in control speakers, and “v” is a sound speed.
d=d0+t×v−λ/2  (1)

A signal processing device includes a coefficient updater configured to calculate a filter coefficient based on a reference signal, an error signal, and an update parameter to set the filter coefficient in a noise cancelling filter. A parameter adjuster adjusts the update parameter according to fluctuation of the reference signal produced from an output of a reference microphone.

In-car communication and hands-free talking with good sound quality are realized. An echo cancelation apparatus (4) is for use in a vehicle in which microphones (M1, M2) and loudspeakers (S1, S2) are disposed in acoustic regions (100, 200). A loudspeaker (S1) and a microphone (M1) are disposed in a first acoustic region (100), and a loudspeaker (S2) and a microphone (M2) are disposed in a second acoustic region (200). An acoustic signal picked up by the microphone (M1) disposed in the first acoustic region (100) is emitted from the loudspeaker (S2) disposed in the second acoustic region (200). An acoustic signal picked up by the microphone (M2) disposed in the second acoustic region (200) is emitted from the loudspeaker (S1) disposed in the first acoustic region (100). The microphone (M1) is designed to hardly collect a sound emitted from the loudspeaker (S2).