An active noise control device includes a first adaptive filter configured to generate a control signal by performing a filtering process on a reference signal corresponding to noise, and a first filter coefficient updating unit configured to update a filter coefficient of the first adaptive filter based on based on the reference signal and an added error signal acquired by adding a first error signal acquired by detecting residual noise by a first microphone and a second error signal acquired by detecting residual noise by a second microphone.

An active noise control device includes a basic signal generating unit configured to generate a basic signal corresponding to a resonance frequency of a vibration sensor, a first adaptive filter configured to generate a sensor resonance simulation signal simulating a signal acquired while the vibration sensor is resonating by performing a filtering process on the basic signal, a computation unit configured to calculate a second reference signal that is a difference between a first reference signal acquired by the vibration sensor and the sensor resonance simulation signal, and a second adaptive filter configured to generate a control signal by performing a filtering process on the second reference signal.

Examples of system for ambient aversive sound detection, identification and management are described. The system comprises an earpiece device with a microphone configured to capture ambient sound around a user and sample it into small segments of the ambient sound, a speaker and a regulator to regulate the ambient sound segment transmitted to the speaker. The system further comprises a processing unit that identifies aversive ambient sound signals in the captured sound segment and provide recommendation action to manage the aversive sound signal by removing, supressing, attenuating or masking the aversive signals.

Method for operating a vehicle-mounted acoustic signal-generating device (8), which is configured to generate an acoustic compensation signal (2) for compensating acoustic interference signals (3), which result from a stream of vehicles (5) coming towards a vehicle (4) in question, comprising the steps: —detection of a stream of vehicles (5) coming towards a vehicle (4) in question, and generation of detection information describing at least one parameter of the stream of vehicles, —determination of an acoustic interference signal (3) resulting from the stream of vehicles (5) coming towards the vehicle (4) in question on the basis of the detection information, —generation of an acoustic compensation signal (2) for compensating the acoustic interference signal (3) resulting from the stream of vehicles (5) coming towards the vehicle (4) in question.

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 active noise cancelling system (20) comprising: an earphone (8′) comprising: an electro-acoustic driver (11); and at least one sensing microphone (12, 13); tunable active noise cancelling circuitry (7) operative to receive a signal from the at least one sensing microphone (12, 13), the tunable active noise cancelling circuitry (7) being pre-configured in a standard tuning for a reference ear and comprising at least one noise-control filter (14, 15); and a tuning module (24) operative to configure the earphone (8′) for an individual wearer by: comparing acoustic coupling of the earphone (8′) to the individual wearer's ear with acoustic coupling to the reference ear to determine a deviation in acoustic coupling; and using the determined deviation in acoustic coupling to modify the tunable active noise cancelling circuitry (7) by a predetermined degree based on the determined deviation in acoustic coupling.

A fan control system applied to N fans inside a computer system is disclosed, comprising: a main microphone, a control circuitry, a wave generation circuitry and a number N of fan controllers. The control circuitry calculates a basic frequency value according to a temperature inside the computer system, and continuously updates a parameter by any known optimization algorithm according to a main audio signal from the main microphone. The wave generation circuitry generates N square waves according to the basic frequency value and the parameter. The N fan controllers respectively form and transmit N modulation signals to the N fans according to the N square waves and N tachometric signals from the N fans. The parameter is one of a frequency variation and a set of phase differences, and the N square waves have the same frequency.

A cooperative control unit is configured to cause a muffled sound control signal processing unit to start feedforward signal processing, and set, when a secondary path filter has converged, a narrow band noise control signal processing unit to the converged secondary path filter and cause the narrow band noise control signal processing unit to start feedback signal processing.

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.

A hybrid ANC system that can allow a feedback microphone to receive the same external noise as a feedforward microphone. A processor can generate an anti-noise signal based on what both microphones received to cancel a broader range of frequencies of the external noise.