A signal processing apparatus is configured to preprocess a sound wave signal and output a processed audio signal through an electromagnetic wave. The signal processing apparatus includes: a receiving unit, configured to receive at least one sound wave signal; a conversion unit, configured to convert the at least one sound wave signal to at least one audio signal; a positioning unit, configured to determine position information related to the at least one sound wave signal; a processing unit, configured to determine a sending time point of at least one audio signal based on the position information and a first time point, where the first time point is a time point at which the receiving unit receives the at least one sound wave signal; and a sending unit, configured to send the at least one audio signal through the electromagnetic wave.

This application discloses a method for reducing an occlusion effect of an earphone, and a related apparatus. The method is applied to an earphone having at least one microphone and a speaker. The method includes: detecting occurrence of at least one of the following events: a user speaks and the user is in a motion state; and triggering at least one of the following operations in response to the at least one event: processing the user's sound signal based on the at least one microphone to suppress an occlusion effect of the earphone, and playing an audio by using the speaker, to mask a sound signal in the user's auditory canal. Embodiments of this application can reduce or even eliminate the earphone occlusion effect, to improve user experience.

Example embodiments may include one or more of receiving sound emissions signals from channels via sound emitters, controlling the sound emission signals, via relay circuits, and one of the relay circuits is configured to interrupt one of the sound emission signals associated with one of the sound emitters while the other sound emissions signals pass to the other corresponding sound emitters, and receiving, via a sound detection circuit, an electrical ambient sound signal based on ambient sound sensed by the one of the sound emitters responsive to the interrupted one of the sound emission signals.

A vehicle that selectively provides important sound to an occupant includes: a microphone configured to receive a noise sound; a speaker; a storage configured to store a plurality of sound waveforms and a warning sound source corresponding to each sound waveform of the plurality of sound waveforms; and a controller configured to generate a noise canceling signal based on the noise sound, control the speaker to output a noise canceling sound corresponding to the noise canceling signal, compare a waveform of the noise sound with the plurality of sound waveforms when a sound pressure level of the noise sound is greater than a threshold value, and when the waveform of the noise sound matches any sound waveform of the plurality of sound waveforms, and control the speaker to play a warning sound source corresponding to the sound waveform matching the noise sound.

Methods and systems are provided for automatic noise control. Automatic noise control includes controlling a shadow noise control transfer function based on a shadow error signal and a filtered or unfiltered reference signal, generating the shadow error signal based on a filtered or unfiltered shadow anti-noise signal and an error signal, and substituting the noise control transfer function by the shadow noise control transfer function if the shadow error signal is smaller than the error signal.

Methods and systems are provided for an automatic noise control system. Automatic noise control includes evaluating an amplitude of an acceleration acting on an acceleration sensor and generating a reference signal representative of the amplitude of the acceleration, the acceleration being representative of unwanted noise sound generated by a noise source, filtering the reference signal with a noise control transfer function to generate an anti-noise signal, and converting with a loudspeaker the anti-noise signal into anti-noise sound.

In one aspect a method that includes receiving an input signal captured by one or more first sensors associated with an active noise reduction (ANR) device, and processing the input signal using a first filter disposed in an ANR signal path to generate a first signal for an acoustic transducer of the ANR device. The input signal is processed in a pass-through signal path disposed in parallel with the ANR signal path to generate a second signal for the acoustic transducer, wherein the pass-through signal path allows a portion of the input signal to pass through to the acoustic transducer in accordance with a variable gain. One or more second sensors detect an existence of a condition likely to cause instability in the pass-through signal path, and in response, the variable gain is adjusted. A driver signal for the acoustic transducer is generated using an output based on the adjusted gain.

An in-ear headphone device for insertion in an ear canal of a person. The in-ear headphone device comprises a noise microphone, a loudspeaker and a signal processor arranged to provide an active noise control signal on the basis of a recorded audio signal from said noise microphone, wherein said loudspeaker is arranged to reproduce said active noise control signal in said ear canal. Further, the device comprises a damped vent comprising one or more vent elements and one or more dampening elements, said damped vent being arranged to couple said ear canal to an external acoustic environment. The damped vent is characterized by an inward vent transfer function HVI from said external acoustic environment to said ear canal. The damped vent is arranged to dampen an acoustic resonance of said one or more vent elements such that a resonance magnitude of said inward vent transfer function HVI of said damped vent in a resonance frequency range from 100 Hz to 2 kHz is maximally 3 dB greater than a reference magnitude of said inward vent transfer function HVI in a reference frequency range from 20 Hz to 100 Hz.

Active noise cancellation systems and methods include a feedforward path configured to receive a reference signal comprising ambient noise and adaptively generate an anti-noise signal to cancel the ambient noise. The adaptive filter is tuned in accordance with at least one parameter, which is set by a logic device configured to determine an ambient noise condition based the reference signal by estimating a fullband power of the reference signal, estimating a low-frequency power of the reference signal, comparing the fullband power and low-frequency power to one or more thresholds, and/or setting one or more ambient noise flags. The ambient noise condition may include a quiet background, a wideband noise condition, and/or a low-frequency dominant noise condition.

Aspects relate to systems and methods for dynamic active noise reduction including at least a sensor configured to sense a physiological characteristic of a user and transmit a physiological signal correlated to the sensed physiological characteristic, at least an environmental microphone configured to transduce an environmental noise to an environmental noise signal, a processor configured to receive the environmental noise signal, generate a noise-reducing sound signal as a function of the environmental noise signal, and, modify the noise-reducing sound signal as a function of the physiological signal, and a speaker configured to transduce a noise-reducing sound from the modified noise-reducing sound signal.