Disclosed are a method for enhancing noise reduction amount of a feedback active noise reduction headphone and active noise reduction headphones. The method includes: arranging a noise reduction microphone of the feedback active noise reduction headphone at a position away from directly in front of a loudspeaker; and adjusting a relative position between the noise reduction microphone and an ear canal opening of a wearer, and enabling an open-loop transfer function at the ear canal opening L2(s0) and an open-loop transfer function at the noise reduction microphone L1(s0) to satisfy a relation of |L2(s0)|>|L1(s0)|, to enhance an actual noise reduction amount at the ear canal opening.

An acoustic system includes: a first customer-side microphone; a first counselor-side microphone; a first sound changing unit; a first loudspeaker; a second customer-side microphone; a second counselor-side microphone; and a second loudspeaker. Between the second loudspeaker and the first customer-side microphone, a first sound transmission path is provided. Also, between the second loudspeaker and the first counselor-side microphone, a second sound transmission path is provided. These sound transmission paths have substantially the same length. The first sound signal generated by the first customer-side microphone is made to have a phase substantially opposite to that of the second sound signal generated by the first counselor-side microphone, and the sound signals are added together.

In a signal processing device, a signal processing method, a recording medium, and a rangehood apparatus, a filter coefficient is set in a sound cancelling filter, and the sound cancelling filter outputs a cancellation signal. A coefficient calculator calculates a first filter coefficient. An oscillation suppressor calculates a second filter coefficient by applying a window function to the first filter coefficient to set the second filter coefficient as the filter coefficient.

Certain aspects provide methods and apparatus for recovering audio quality of voice when processing signals associated with a wearable audio output device. A method that may be performed includes receiving. by an in-ear microphone acoustically coupled to an environment inside an car canal of a user, an audio signal having a first frequency band. predicting high-frequency band information for the audio signal using a model trained using training data of known high-frequency bands associated with low-frequency bands. generating an output signal having a second frequency band based. at least in part. on the first frequency band of the audio signal and the predicted high-frequency band information for the audio signal, and outputting. by the wearable audio output device. the output signal having the second frequency band.

A silencer is to be used in combination with a range hood system to suppress noise made by a fan. In a silencing circuit, a disturbance detector detects mixing of disturbance sound to a correction signal and an error signal. When the disturbance detector detects the mixing of the disturbance sound, an updating stopper causes a coefficient updater to stop a processing of updating a filter coefficient of a silencer filter, relating to, as an object, at least a frequency band other than a frequency band of the noise.

An electronic device and a noise cancelation method thereof are provided. The electronic device includes a driver, a driven device, and an inertial measurement device. The driver is configured to generate a driving signal, and generate a noise prediction signal according to the driving signal. The driven device receives the driving signal to execute an operation, wherein the driven device generates a vibration noise according to generated vibrations when executing the operation. The inertial measurement device is configured to sense a position status of the electronic device to generate sensing information. The inertial measurement device receives the noise prediction signal, and compensates the sensing information according to the noise prediction signal to generate compensated sensing information.

An electronic device and a noise cancelation method thereof are provided. The electronic device includes a driver, a driven device, and an inertial measurement device. The driver is configured to generate a driving signal, and generate a noise prediction signal according to the driving signal. The driven device receives the driving signal to execute an operation, wherein the driven device generates a vibration noise according to generated vibrations when executing the operation. The inertial measurement device is configured to sense a position status of the electronic device to generate sensing information. The inertial measurement device receives the noise prediction signal, and compensates the sensing information according to the noise prediction signal to generate compensated sensing information.

A method of calibrating an earphone may include: securing an ANC earphone to a calibration fixture, the calibration fixture including an ear model configured to support the ANC earphone, the ear model having an ear canal configured to anatomically resemble a human ear canal and a concha configured to anatomically resemble a human ear concha, the ear canal extending from the concha to an inner end of the ear canal; generating, with the ANC earphone, an audio signal based on a reference tone; determining a characteristic of the audio signal; comparing the characteristic of the audio signal to a previously determined reference characteristic; and adjusting a gain value of the ANC earphone based on the comparing. Additional methods and apparatus are also disclosed.

A method of calibrating an earphone may include: securing an ANC earphone to a calibration fixture, the calibration fixture including an ear model configured to support the ANC earphone, the ear model having an ear canal configured to anatomically resemble a human ear canal and a concha configured to anatomically resemble a human ear concha, the ear canal extending from the concha to an inner end of the ear canal; generating, with the ANC earphone, an audio signal based on a reference tone; determining a characteristic of the audio signal; comparing the characteristic of the audio signal to a previously determined reference characteristic; and adjusting a gain value of the ANC earphone based on the comparing. Additional methods and apparatus are also disclosed.

An open wearable acoustic device and an active noise reduction method are provided. The acoustic device includes a first sound sensor module, a speaker, and a noise reduction circuit. The first sound sensor module includes N sound sensors. The noise reduction circuit determines, based on a target direction from which ambient noise comes, N weights corresponding to the N sound sensors, so that a phase of an integrated ambient noise signal measured by the first sound sensor module based on the N weights is ahead of a phase of the ambient noise reaching a sound output end of the speaker. The noise reduction circuit generates a first noise cancellation signal based on N individual ambient noise signals captured by the N sound sensors, and the N weights. The speaker converts the first noise cancellation signal into a first noise cancellation audio, thereby achieving noise reduction.