Abstract: The technology described in this document can be embodied in a method that includes receiving an input signal representing audio captured by one or more sensors of an active noise reduction (ANR) headphone, and generating, based on the input signal, a first signal by a compensator disposed in an ANR signal flow path. The method also includes determining one or more characteristics of the first signal, and selecting, based on the one or more characteristics of the first signal, a plurality of filter coefficients for a digital filter disposed in series with the compensator in the ANR signal flow path. The filter coefficients are selected in accordance with a target frequency response of the digital filter. The method further includes generating, by processing the input signal using the plurality of filter coefficients of the digital filter, a feedback control signal for an electroacoustic transducer of the ANR headphone.

Abstract: The technology described in this document can be embodied in a method that includes receiving an input signal representing audio captured by one or more sensors of an active noise reduction (ANR) headphone, and generating, based on the input signal, a first signal by a compensator disposed in an ANR signal flow path. The method also includes determining one or more characteristics of the first signal, and selecting, based on the one or more characteristics of the first signal, a plurality of filter coefficients for a digital filter disposed in series with the compensator in the ANR signal flow path. The filter coefficients are selected in accordance with a target frequency response of the digital filter. The method further includes generating, by processing the input signal using the plurality of filter coefficients of the digital filter, a feedback control signal for an electroacoustic transducer of the ANR headphone.

Abstract: The technology described in this document can be embodied in a method that includes receiving an input signal representing audio captured by a microphone of an active noise reduction (ANR) headphone, and processing, by a first compensator, a first frequency range of the input signal to generate a first signal for an acoustic transducer of the ANR headphone. The method also includes processing, by a second compensator disposed in parallel to the first compensator, a second frequency range of the input signal to generate a second signal for the acoustic transducer. The first frequency range includes frequencies higher than the frequencies in the second frequency range. The method also includes detecting, by one or more processing devices, that the second signal satisfies a threshold condition, and attenuating the second signal responsive to determining that the second signal satisfies the threshold condition.

Abstract: The technology described in this document can be embodied in a method that includes receiving an input signal captured by one or more sensors associated with an active noise reduction (ANR) headphone, and determining one or more characteristics of a first portion of the input signal. Based on the one or more characteristics of the first portion of the input signal, a gain of a variable gain amplifier (VGA) disposed in an ANR signal flow path can be adjusted, and accordingly, a set of coefficients for a tunable digital filter disposed in the ANR signal flow path can be selected. The method further includes processing a second portion of the input signal in the ANR signal flow path using the adjusted gain and selected set of coefficients to generate a second output signal for the electroacoustic transducer of the ANR headphone.

Abstract: An earphone includes an acoustic transducer and a housing that includes a first acoustic chamber acoustically coupled to a first side of the acoustic transducer and a second acoustical chamber acoustically coupled to a second side of the acoustic transducer. The housing further includes a port acoustically coupling the first acoustic chamber and the second acoustic chamber. Acoustic resistive material is positioned proximate the port.

Abstract: A method of controlling a personal acoustic device includes performing a first analysis of one or more of an inner signal output by an inner microphone and an outer signal output by an outer microphone disposed on the personal acoustic device to determine if a buffet event has occurred. A second analysis is performed on or both of the inner and outer signals to determine if a voice event of a user occurred. If a buffet event is determined to have occurred and a voice event is determined not to have occurred, a third analysis is performed on the inner and outer signals to determine an operating state of the personal acoustic device. If a change in the operating state is determined, an operation of the personal acoustic device may be initiated such as changing a power state, an ANR state or an audio output state of the device.

Abstract: A method of controlling a personal acoustic device includes performing a first analysis of one or more of an inner signal output by an inner microphone and an outer signal output by an outer microphone disposed on the personal acoustic device to determine if a buffet event has occurred. A second analysis is performed on or both of the inner and outer signals to determine if a voice event of a user occurred. If a buffet event is determined to have occurred and a voice event is determined not to have occurred, a third analysis is performed on the inner and outer signals to determine an operating state of the personal acoustic device. If a change in the operating state is determined, an operation of the personal acoustic device may be initiated such as changing a power state, an ANR state or an audio output state of the device.

Abstract: An earphone includes an acoustic transducer and a housing that includes a first acoustic chamber acoustically coupled to a first side of the acoustic transducer and a second acoustical chamber acoustically coupled to a second side of the acoustic transducer. The housing further includes a port acoustically coupling the first acoustic chamber and the second acoustic chamber. Acoustic resistive material is positioned proximate the port.