A signal e(z) obtained by subtracting echo-canceling sound from an output of a second microphone is used as an error of an echo cancellation adaptive filter and a noise cancellation adaptive filter, and an output of a first sound source device is added to the signal e(z) and output from a first speaker. The echo cancellation adaptive filter generates echo-canceling sound from an addition signal of the output of the second sound source device and the output of the first microphone such that the signal e(z) is minimized. The noise cancellation adaptive filter generates the noise-canceling sound from the output of the first sound source device such that the signal e(z) is minimized, and outputs the noise-canceling sound from the second speaker.

A computer-implemented method for automatically designing a feedforward filter that is optimized for an audio transparency mode of operation of an audio device, the audio device comprising the feedforward filter and a feedback filter, the method comprising optimizing the feedforward filter for the audio transparency mode of operation, wherein optimization of the feedforward filter is dependent on the feedback filter.

A system and method for quieting unwanted sound. As a non-limiting example, various aspects of this disclosure provide a system and method, for example implemented in a premises-based or home audio system, for quieting unwanted sound at a particular location.

A vehicle audio system is provided with at least one loudspeaker to project sound within a room in response to receiving an audio signal. A controller is programmed to generate the audio signal based on at least one occupancy signal indicative of occupant presence and identification within the room, wherein the audio signal is indicative of at least one of anti-noise sound, synthesized engine noise (SEN), and music.

An active noise control (ANC) circuit is used for generating an anti-noise signal, and has a plurality of filters including at least one first filter and at least one second filter. The at least one first filter generates at least one first filter output, wherein each of the at least one first filter has at least one non-static filter and at least one static filter connected in a series fashion. The at least one second filter generates at least one second filter output, wherein each of the at least one second filter has at least one adaptive filter. The anti-noise signal is jointly controlled by the at least one first filter output and the at least one second filter output. The at least one first filter and the at least one second filter are connected in a parallel fashion.

A system and method for quieting unwanted sound. As a non-limiting example, various aspects of this disclosure provide a system and method, for example implemented in a premises-based or home audio system, for quieting unwanted sound at a particular location.

In at least one embodiment, an active noise cancellation (ANC) system is provided. The ANC system includes at least one loudspeaker, at least one microphone, and a reference generator. The at least one loudspeaker projects anti-noise sound within a cabin of a vehicle based at least on an estimated reference signal and an anti-noise signal. The at least one microphone to provide a first error signal indicative of noise and the anti-noise sound within the cabin. The at least one filter controller programmed to receive the first error signal and the estimated reference signal; and to control at least one adaptive filter to generate the anti-noise signal based at least on the first error signal and the estimated reference signal. The reference generator is programmed to generate the estimated reference signal based at least on one of vehicle speed, temperature of a tire of the vehicle, or tire pressure.

Embodiments of this application disclose a noise cancellation apparatus and method. The noise cancellation apparatus includes a main control unit and a noise cancellation processing circuit. The main control unit determines a noise cancellation parameter based on a noise cancellation level index or a feature value for determining a matching degree between a headset and an ear canal of a user. The noise cancellation processing unit obtains an inverse phase noise of an ambient noise based on the noise cancellation parameter. After the inverse phase noise is mixed with a played downlink audio signal, the ambient noise can be canceled. In addition, because the noise cancellation parameter is determined from a preset noise cancellation parameter library based on the received or autonomously determined noise cancellation level index, instead of being uniformly configured, a noise cancellation level can be flexibly adjusted, thereby improving a noise cancellation effect and user experience.

A method of operating a headphone configured to be removed from and placed in close proximity to a user's ear can include generating an input signal by an input signal generating device. The method can also include determining whether an insertion event has occurred based on the generated input signal and causing the headphone to operate in a low power mode responsive to an absence of an insertion event determination after a first period of time. The method can also include causing the headphone to operate in an ultra-low power mode responsive to the absence of an insertion event determination after a second period of time that occurs after the first period of time, the ultra-low power mode having a lower power consumption than the low power mode.

A method of operating a personal audio device configured to be removed from and inserted into a user's ear can include generating an input signal by an input signal generating device. The method can also include determining whether an insertion event has occurred based on the generated input signal and causing the personal audio device to operate in a low power mode responsive to an absence of an insertion event determination after a first period of time. The method can also include causing the personal audio device to operate in an ultra-low power mode responsive to the absence of an insertion event determination after a second period of time that occurs after the first period of time, the ultra-low power mode having a lower power consumption than the low power mode.