By performing both noise cancellation and echo cancellation, a high-quality main voice signal is generated. A voice input/output apparatus includes a noise acquirer that is arranged toward an outside of a body of a user and acquires external noise arriving from the outside of the user, a voice output unit that accepts an input of a voice signal and outputs a voice to an ear canal of the user, a main voice acquirer that acquires a mixed voice, in which the external noise, the output voice, and a main voice of the user transmitted from a vocal cord of the user through the ear canal are mixed, and outputs a mixed voice signal, a noise canceler that processes the mixed voice signal using a noise signal based on the external noise, and an echo canceler that processes the mixed voice signal using the voice signal.

Methods, systems, computer-readable media, devices, and apparatuses for synchronized mode transitions are presented. A first device configured to be worn at an ear includes a processor configured to, in a first contextual mode, produce an audio signal based on audio data. The processor is also configured to, in the first contextual mode, exchange a time indication of a first time with a second device. The processor is further configured to, at the first time, transition from the first contextual mode to a second contextual mode based on the time indication.

An apparatus includes a hybrid adaptive active noise control unit (HAANCU) configured to provide an anti-noise signal to an ear speaker from a reference noise signal of a reference microphone and an error signal of an error microphone, a decimator configured to decimate the reference noise signal and error signal, an adaptive hybrid ANC training unit (AHANCTU) including at least one noise cancellation filter and a filter configured to provide a feedback signal to the at least one noise cancellation, which trains parameters of the AHANCTU based on the decimated reference noise signal, the decimated error signal, and the feedback signal. The apparatus further includes a rate conversion unit configured to up-sample the parameters and update the HAANCU with the up-sampled parameters.

A noise-canceling headrest for a vehicle seat, comprising a central part and two side parts, at least one loudspeaker, a microphone, an audio source playback module capable of transmitting an audio signal to the loudspeaker, a noise sensor, and a signal processing circuit configured for: receiving a noise signal and determining a noise correction function, receiving an error signal from the microphone, and updating the noise correction function, generating a noise correction signal by applying the noise correction function to the noise signal, generating a control signal intended for the loudspeaker, by adding together the noise correction signal and the audio signal.

A design method for feedforward active noise control system is disclosed. Based on a target signal and a reference signal, a first adaptive system identifying unit is enabled to complete a first system identification process for producing a first adaptive filter, and then a second adaptive system identifying unit is enabled to complete a second system identification process for producing a second adaptive filter. After the second adaptive filter is converted to a digitally-controlled filter by using a system identification tool, the digitally-controlled filter is implemented into a DSP chip of a feedforward active noise control system. As a result, it is able to find that not only the computing loading of the DSP chip is significantly lowered while an adaptive algorithm executes an active noise control computing, but also the feedforward active noise control system exhibits a broad frequency bandwidth noise cancelling ability.

A feedback noise reduction method, a feedback noise reduction system, and an earphone are provided. In the method, a channel morphological parameter of an acoustic channel between a microphone and a speaker in a feedback noise reduction system is detected; the feedback noise reduction system is switched from using a first noise reduction filter to using a second noise reduction filter in a case that it is determined that the acoustic channel is in an interfered state based on the channel morphological parameter; and a noise reduction signal is generated by using the second noise reduction filter to cancel a noise signal received by the feedback noise reduction system. A frequency response of the second noise reduction filter in a predetermined frequency band is less than a frequency response of the first noise reduction filter in the predetermined frequency band.

An internal microphone signal of a headphone is filtered by i) a first filter G that, as part of an acoustic noise cancellation, ANC, subsystem, produces an anti-noise audio signal, and ii) a second filter C to produce a feedback audio signal. An estimate of a transfer function of a path S is determined, wherein the path S is from i) an input of a speaker of the headphone to ii) the internal microphone signal. The second filter C is adapted based on the estimate of the transfer function of the path S drives an input of a speaker of the headphone. Other embodiments are also described.

Provided is a technology for generating an elimination filter coefficient for suppressing degradation of noise elimination performance. An elimination filter coefficient generation method for inputting a reference signal output from a reference microphone for collecting noise and an error signal output from an error microphone for collecting sound at a position that needs to be silent, and generating an elimination filter coefficient used for filtering for generating an elimination signal for eliminating noise at the position that needs to be silent from the reference signal includes: a route filtering step for generating a filtered reference signal from the reference signal by filtering using a route filter coefficient indicating acoustic characteristics of a route from a speaker for emitting sound based on the elimination signal to the error microphone; a first noise signal generation step for generating a predetermined signal as a first noise signal; a noise signal addition step for generating an added reference signal from the filtered reference signal and the first noise signal; and an elimination filter coefficient generation step for generating the elimination filter coefficient from the error signal and the added reference signal.

A noise canceling adaptive filter outputs, from a front seat speaker, a noise canceling sound generated by applying a transfer function X(z) adapted by an adaptive operation using an output of a front seat microphone as an error to an output sound of a sound source apparatus. An output of the front seat microphone is added to an output of an audio feedback canceling filter by a second adder, added to an output sound of the sound source apparatus by a third adder, and output from a rear seat speaker. The audio feedback canceling filter applies a transfer function X′(z) and a transfer function C^(z) on an output of the second adder and outputs a resultant. The transfer function C^(z) corresponds to a transfer function C(z) from the front seat speaker to the front seat microphone. In synchronization control, the transfer function X(z) is set as the transfer function X′(z).

By performing both noise cancellation and echo cancellation, a high-quality main voice signal is generated. A voice input/output apparatus includes a noise acquirer that is arranged toward an outside of a body of a user and acquires external noise arriving from the outside of the user, a voice output unit that accepts an input of a voice signal and outputs a voice to an ear canal of the user, a main voice acquirer that acquires a mixed voice, in which the external noise, the output voice, and a main voice of the user transmitted from a vocal cord of the user through the ear canal are mixed, and outputs a mixed voice signal, a noise canceler that processes the mixed voice signal using a noise signal based on the external noise, and an echo canceler that processes the mixed voice signal using the voice signal.