A system includes a first earpiece having an earpiece housing configured to isolate an ambient environment from a tympanic membrane by physically blocking ambient sound, a microphone disposed within the housing and configured to receive a first ambient audio signal from the ambient environment, a processor operatively connected to the microphone wherein the processor is configured to receive the first ambient audio signal from the microphone and determine if the first ambient signal exceeds a threshold sound level, and a speaker operatively connected to the processor. In a first mode of operation the processor determines the first ambient audio signal exceeds the threshold sound level and processes the first ambient audio signal to modify the first ambient audio signal. In a second mode of operation the processor determines the first ambient audio signal does not exceed the threshold sound level and reproduces the first ambient audio signal at the speaker.

An active road-noise control system and method include using a sensor arrangement to generate a first sense signal representative of at least one acceleration, motion and/or vibration that occurs at a first position on a vehicle body and a second sense signal representative of sound that occurs at a second position within the vehicle body; they also provide a noise-reducing signal by processing the sense signals according to a first or a second mode of operation. They include the generation of noise-reducing sound within the vehicle body at the second position from the noise reducing signal and the operational state of the sensor arrangement; the first sense signal and the second sense signal are processed in the first mode when the sensor arrangement is in a proper operational state and in the second mode when a malfunction of the sensor arrangement has been detected.

In a noise reduction device that generates and outputs a control sound signal for reducing noise, an internal loop control unit controls an internal loop in which a pre-output control sound signal that is acquired from a control sound output unit before output to a speaker is input to a sound receiver. A measurement unit measures an input level of a microphone sound signal and an input level of the pre-output control sound signal that has been input to the sound receiver in the internal loop. A fault detector uses the input level of the microphone sound signal and the input level of the pre-output control sound signal measured by the measurement unit to detect a fault in any one of the microphone, the sound receiver, the speaker, and the control sound output unit. A transmitter sends a result of fault detection performed by the fault detector to a management device.

A system and method for reducing or eliminating undesirable acoustic artifacts when a vehicle is struck by road debris. The method includes generating a noise signal representative of a first acceleration detected by an accelerometer of a vehicle caused by a disturbance and generating a noise-cancellation signal via a controller within the vehicle. Residual noise resulting from the combination of the acoustic energy of the noise-cancellation signal and the disturbance is detected by a reference sensor, which generates a reference sensor signal based on the residual noise. The reference sensor signal is transmitted to an adaptive processing module to adapt filter coefficients. A second acceleration is detected by the accelerometer and a level detector calculates the absolute value of a derivative of the second acceleration. If the absolute value exceeds a threshold value, adjustment of the filter coefficients is prevented.

An active noise control device reduces noise inside a cabin of a car. The active noise control device includes: a controller that decreases a signal level of a canceling signal when a signal level of a received reference signal is lower than a threshold; and a threshold controller that changes the threshold based on at least one of a signal level of an error signal and information on the car.

A noise-cancellation system, including: a plurality of sensors, each sensor outputting a sensor signal; a controller configured to receive each sensor signal, and, for each sensor signal, to: determine a power of the sensor signal at a plurality of frequencies; determine a measure of association between the power of the sensor signal at the plurality of frequencies and frequency; and determine whether the measure of association exceeds a predetermined threshold, wherein the processor is further configured to compute a noise-cancellation signal using the sensor signals, wherein the noise-cancellation signal is computed excluding sensor signals that were determined to exceed the predetermined threshold; and at least one actuator receiving the noise-cancellation signal and producing a noise-cancellation audio signal.

An electronic device is provided. The electronic device includes an audio module including a plurality of audio reception units and a plurality of audio output units and a processor electrically connected to the audio module and configured to receive sound via the plurality of audio reception units, generate antiphase signals based on waveforms of the received sound, determine directions in which to emit the antiphase signals, based on locations of the plurality of audio reception units, and emit the antiphase signals via the plurality of audio output units.

An active noise reduction device includes: a reference signal input terminal that receives a reference signal outputted by a reference signal source and having a correlation with noise in a space in an automobile, the reference signal source being attached to the automobile; a test signal source that outputs a test signal to a loudspeaker attached to the automobile, the loudspeaker being used to output a canceling sound for reducing the noise; and an anomaly determiner that determines whether the reference signal source has an anomaly, based on the reference signal inputted from the reference signal source to the reference signal input terminal when the test signal is outputted to the loudspeaker.

A road noise cancellation (RNC) system may include a noise controller for detecting non-stationary events, such as objects striking vibration sensors, based on sensor signals having a spectral character significantly different from steady-state road noise. Upon detection of an object strike, the RNC system may be deactivated or certain speakers may be muted. Alternatively, the RNC system may modify the sensor signals to mask the non-stationary event, thereby preventing the RNC system from generating anti-noise based on the object strike.

An active vibration and noise control device robust against outside disturbances, and an active vibration and noise control circuit are provided. An adaptive control circuit of this active vibration and noise control device has autocorrelation value calculation units which calculate an autocorrelation value of an error signal or of a target signal, which is a reference signal or a standard signal, and a canceling output limiting unit which determines whether or not an autocorrelation value is less than an autocorrelation threshold value, and limits increases in the cancelling output if it is determined that the autocorrelation value is less than the autocorrelation threshold value.