An audio system for an ear mountable playback device comprises a speaker, an error microphone predominantly sensing sound being output from the speaker and a feed-forward microphone predominantly sensing ambient sound. The audio system further comprises a voice activity detector which is configured to record a feed-forward signal from the feed-forward microphone. Furthermore, an error signal is recorded from the error microphone. A detection parameter is determined as a function of the feed-forward signal and the error signal. The detection parameter is monitored and a voice activity state is set depending on the detection parameter.

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).

An audio system for an ear mountable playback device comprises a speaker, an error microphone configured to predominantly sense sound being output from the speaker and a further microphone configured to predominantly sense ambient sound. The system further comprises a first noise filter coupling the further microphone to the speaker, a second noise filter coupling the error microphone to the speaker and an adaptation engine. The adaptation engine is configured to adapt a response of the first noise filter depending on error signals from at least the error microphone, estimate a leakage condition from the response of the first noise filter, and adapt a response of the second noise filter depending on the estimated leakage condition.

Exemplary road and engine noise control systems and methods include directly picking up road noise from a structural element of a vehicle to generate a first sense signal representative of the road noise, directly picking up engine noise from an engine of the vehicle to generate a second sense signal representative of the engine noise, and combining the first sense signal and the second sense signal to provide a combination signal representing the combination of the first sense signal and the second sense signal. The systems and methods further include broadband active noise control filtering to generate a filtered combination signal from the combination signal, converting the filtered combination signal provided by the active noise control filtering into anti-noise and radiating the anti-noise to a listening position in an interior of the vehicle. The filtered combination signal is configured so that the anti-noise reduces the noise at the listening position.

A method reduces echo in a hearing instrument. A first input transducer generates a first input signal from ambient sound. A communication unit receives an external input signal from an external device. The first input signal and the external input signal are used to generate an output signal. The output signal is used in a first filter to generate a compensation signal for reducing echo and/or acoustic feedback. The first input signal and the compensation signal are used to generate an error signal. Filter coefficients of the first filter and/or a comparison of the error signal with the compensation signal and/or with the first input signal are/is used to generate a control variable. The control variable is taken as a basis for applying a second filter for rejecting a residual echo or a residual feedback to an intermediate signal derived from the input signal, and a transmission signal is generated.

Adaptive filters output a cancellation sound from a speaker, a selector selects outputs of a plurality of auxiliary filters each corresponding to different positions, a subtractor subtracts the selected output from the output of the microphone and outputs the subtracted output to the adaptive filter as an error signal, and a position detection device detects a position of a head of a user. A transfer function estimated so that the error signal becomes 0 when noise is canceled at the corresponding position is preset in the auxiliary filter. When the auxiliary filter corresponding to the position close to the head of the user changes, the switching control unit stepwise increases the frequency with which the output of the auxiliary filter is selected by the selector to 100%.

There is provided an ear cup comprising a housing, an ear pad attached to the housing and arranged such that the housing and the ear pad together define a cavity having an opening, and an acoustic driver disposed within the cavity. The ear cup further comprises a feedforward microphone, a feedback microphone, and active noise control (ANC) circuitry. The active noise control (ANC) circuitry is configured to use a feedforward signal provided by the feedforward microphone to operate the acoustic driver to attenuate noise having frequencies within a feedforward ANC range having a lower limit of no less than 300 Hz and an upper limit of more than 1.5 kHz and to use a feedback signal provided by the feedback microphone to operate the acoustic driver to attenuate noise having frequencies within a feedback ANC range having an upper limit of no more than 1.5 kHz.

A system configured to perform deep adaptive acoustic echo cancellation (AEC) to improve audio processing. Due to mechanical noise and continuous echo path changes caused by movement of a device, echo signals are nonlinear and time-varying and not fully canceled by linear AEC processing alone. To improve echo cancellation, deep adaptive AEC processing integrates a deep neural network (DNN) and linear adaptive filtering to perform echo and/or noise removal. The DNN is configured to generate a nonlinear reference signal and step-size data, which the linear adaptive filtering uses to generate output audio data representing local speech. The DNN may generate the nonlinear reference signal by generating mask data that is applied to a microphone signal, such that the reference signal corresponds to a portion of the microphone signal that does not include near-end speech.

An acoustic device includes a detection unit configured to detect a timing to transition to each of a first power-saving mode and a second power-saving mode, a battery, a monitoring unit configured to monitor a remaining capacity of the battery, a signal processing unit configured to process a sound signal, a sound emitting unit configured to acoustically output the processed sound signal, a communication unit configured to transmit and receive a signal to and from a communication terminal and transmit the processed sound signal to the communication terminal, and a control unit configured to stop an operation of the signal processing unit based on the detection of the timing to transition to the first power-saving mode.