An ANC system is provided, including an AD converter performing an AD conversion on an external noise signal; an ANC signal generator generating an ANC signal for canceling a noise component arriving at ears of a user based on an output signal of the AD converter; a level detector detecting a level of the output signal and causes the ANC signal generator to power down in response to the level; and a zero-cross detector detecting a zero-cross timing of the ANC signal. The level detector starts measuring a time when the level is equal to or less than a first threshold value, and causes the ANC signal generator to perform a power down operation when the zero-cross timing is detected after the measured time exceeds the predetermined value, and causes the ANC signal generator to exit from the power down operation when the level exceeds a second threshold value.

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.

Disclosed is a signal processing apparatus including a surrounding sound signal acquisition unit, a NC (Noise Canceling) signal generation part, a cooped-up feeling elimination signal generation part, and an addition part. The surrounding sound signal acquisition unit collects a surrounding sound to generate a surrounding sound signal. The NC signal generation part generates a noise canceling signal from the surrounding sound signal. The cooped-up feeling elimination signal generation part generates a cooped-up feeling elimination signal from the surrounding sound signal. The addition part adds together the generated noise canceling signal and the cooped-up feeling elimination signal at a prescribed ratio.

A system comprises automatic noise cancellation circuitry and interface circuitry operable to provide an interface via which a user can configure which sounds said automatic noise cancelling circuitry attempts to cancel and which sounds said automatic noise cancelling circuitry does not attempt to cancel. The interface circuitry may be operable to provide an interface via which a user can select a sound to whitelist or blacklist. The interface circuitry may be operable to provide an interface via which a user can increase or decrease an amount of noise cancellation that is desired. The interface circuitry may be operable to provide an interface via which a user can select from among three or more levels of noise cancellation.

An embodiment electromyography signal detection device includes a noise signal obtaining device configured to obtain a noise signal of an unknown reference frequency at a periphery of a user, an electromyography signal acquisition device configured to measure an electromyography signal from the user, and a controller configured to remove a noise signal included in the electromyography signal of the user based on the obtained noise signal of the unknown reference frequency.

Disclosed is a signal processing apparatus including a surrounding sound signal acquisition unit, a NC (Noise Canceling) signal generation part, a cooped-up feeling elimination signal generation part, and an addition part. The surrounding sound signal acquisition unit collects a surrounding sound to generate a surrounding sound signal. The NC signal generation part generates a noise canceling signal from the surrounding sound signal. The cooped-up feeling elimination signal generation part generates a cooped-up feeling elimination signal from the surrounding sound signal. The addition part adds together the generated noise canceling signal and the cooped-up feeling elimination signal at a prescribed ratio.

Disclosed is a signal processing apparatus including a surrounding sound signal acquisition unit, a NC (Noise Canceling) signal generation part, a cooped-up feeling elimination signal generation part, and an addition part. The surrounding sound signal acquisition unit is configured to collect a surrounding sound to generate a surrounding sound signal. The NC signal generation part is configured to generate a noise canceling signal from the surrounding sound signal. The cooped-up feeling elimination signal generation part is configured to generate a cooped-up feeling elimination signal from the surrounding sound signal. The addition part is configured to add together the generated noise canceling signal and the cooped-up feeling elimination signal at a prescribed ratio.

Vertical take-off and landing (VTOL) aircraft can provide opportunities to incorporate aerial transportation into transportation networks for cities and metropolitan areas. However, VTOL aircraft may be noisy. To accommodate this, the aircraft may utilize onboard sensors, offboard sensing, network, and predictive temporal data for noise signature mitigation. By building a composite understanding of real data offboard the aircraft, the aircraft can make adjustments to the way it is flying and verify this against a predicted noise signature (via computational methods) to reduce environmental impact. This might be realized via a change in translative speed, propeller speed, or choices in propulsor usage (e.g., a quiet propulsor vs. a high thrust, noisier propulsor). These noise mitigation actions may also be decided at the network level rather than the vehicle level to balance concerns across a city and relieve computing constraints on the aircraft.

The technology described in this document can be embodied in a method that includes receiving an input signal representing audio captured by a microphone of an active noise reduction (ANR) headphone, processing, by one or more processing devices, a portion of the input signal to determine a noise level in the input signal, and determining that the noise level satisfies a threshold condition. The method also includes, in response to determining that the noise level satisfies the threshold condition, generating an output signal in which ANR processing on the input signal is controlled in accordance with a target loudness level of the output signal, and driving an acoustic transducer of the ANR headphone using the output signal.

An active noise reduction system includes a substrate, a number of capacitors mounted on the substrate, a noise sensor mounted on the substrate and used to collect a noise signal around the noise sensor, an actuator mounted on the substrate and used to generate vibrations, and a controller mounted on the substrate and electrically coupled to the noise sensor and the actuator. The controller is used to obtain the noise signal collected by the noise sensor and generate a control signal according to the noise signal to the actuator to control the actuator to generate vibrations having a same frequency and opposite phase as the noise signal to cancel out the vibrations generated by the plurality of capacitors and the vibrations of the substrate caused by the vibrations generated by the plurality of capacitors. An electronic device and an active noise reduction method are also provided.