The technology described this document can be embodied in a method that includes receiving an error signal captured using a microphone, the error signal representing a difference between the sinusoidal component of a noise signal and an output of an acoustic transducer. The output of the acoustic transducer is configured to reduce the effects of the sinusoidal component of the noise signal. The method includes processing the error signal to compensate for effects due to a signal path between the acoustic transducer and the microphone, and determining a current estimate of one or more first parameters of the error signal. Based on such parameters, a current estimate of a time-varying step size associated with an adaptive process is determined, and based on the current estimate of the time-varying step size, a driver signal configured to change the output of the acoustic transducer is generated.

A method may include receiving a user trigger signal indicating a user desire to update characteristics of an adaptive filter, receiving an error microphone signal indicative of the output of the transducer and the ambient audio sounds at the transducer, wherein the transducer reproduces both a source audio signal for playback to a listener and an anti-noise signal for countering the effects of ambient audio sounds in an acoustic output of the transducer, implementing the adaptive filter having a response that generates the anti-noise signal to reduce the presence of the ambient audio sounds in the error microphone signal, determining an acoustic coupling of the transducer to an error microphone for producing the error microphone signal, and responsive to a change in the acoustic coupling, prompting a user to assert the user trigger signal to indicate user desire to update characteristics of the adaptive filter.

A sound system is provided with a headphone that includes a transducer and at least one microphone. The sound system also includes an equalization filter and a loop filter circuit. The equalization filter is adapted to equalize an audio input signal based on at least one predetermined coefficient. The loop filter circuit includes a leaky integrator circuit that is adapted to generate a filtered audio signal based on the equalized audio input signal and a feedback signal indicative of sound received by the at least one microphone, and to provide the filtered audio signal to the transducer.

Active noise control system and methods are disclosed that include generating anti-noise that is configured to reduce or cancel noise occurring at a listening position in the ambiance of a seat with a backrest enclosing a hollow volume. Radiating the anti-noise from within the hollow volume of the backrest of the seat.

With the noise reduction device (300), in identifying an acoustic transfer function that includes a path from the control speaker (340) to the error microphone (350) or the noise microphone (320) by outputting an identification sound from the control speaker (340) and detecting the identification sound with the error microphone (350) or the noise microphone (320), the identification controller (338) is configured to identify the acoustic transfer function by generating the identification sound from the white noise generator (337) when the seat detector (582) has detected that the seat is in the actual usage state for noise reduction.

An active noise cancellation (ANC) system may include an adaptive filter divergence detector for detecting divergence of the one or more controllable filters as they adapt, based on dynamically adapted thresholds. Upon detection of a controllable filter divergence, the ANC system may be deactivated, or certain speakers may be muted. Alternatively, the ANC system may modify the diverged controllable filters to restore proper operation of the noise cancelling system.

A system and method for integrating a home media system and other home systems. As a non-limiting example, various aspects of this disclosure provide a system and method that flexibly and efficiently provide communication and/or resource sharing between a home media system and various other home systems.

Active noise reduction (ANR) headphones and associated methods are provided. The ANR headphones may include a memory to store a plurality of profiles each including controller information and acoustic parameters in addition to a profile selection routine executable by a processor of the ANR headphone. The profile selection routine may be configured to identify acoustic characteristics of a subject wearing the ANR headphone, compare the acoustic characteristics of the subject with the acoustic parameters of the plurality of profiles, select a profile from the plurality of profiles based on the comparison between the acoustic characteristics of the subject with the acoustic parameters of the selected profile, and provide the controller information of the selected profile to a noise reduction circuit of the ANR headphone.

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.

A system and method for integrating a home media system and other home systems. As a non-limiting example, various aspects of this disclosure provide a system and method that flexibly and efficiently provide communication and/or resource sharing between a home media system and various other home systems.