Abstract: Technology described in this document can be embodied in a method that includes receiving a first input signal representing audio captured by a first sensor disposed in a signal path of an active noise reduction (ANR) device, and receiving a second input signal representing audio captured by a second sensor disposed in the signal path of the ANR device. The method also includes processing, by at least one compensator, the first input signal and the second input signal to generate a drive signal for an acoustic transducer of the ANR device. A gain applied to the signal path is at least 3 dB less relative to an ANR signal path having a single sensor.

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: Technology described in this document can be embodied in a method that includes receiving a first input signal representing audio captured by a first sensor disposed in a signal path of an active noise reduction (ANR) device, and receiving a second input signal representing audio captured by a second sensor disposed in the signal path of the ANR device. The method also includes processing, by at least one compensator, the first input signal and the second input signal to generate a drive signal for an acoustic transducer of the ANR device. A gain applied to the signal path is at least 3 dB less relative to an ANR signal path having a single sensor.

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: A headphone includes an electro-acoustic transducer for creating audio output, the electro-acoustic transducer comprising a transducer magnet that produces a transducer magnetic field having a magnetic field strength, a housing constructed and arranged to be positioned at an ear of a wearer so as to direct the audio output at the ear canal of the ear, a magnetic field sensor positioned in the housing and constructed and arranged to sense the Earth's magnetic field, and a nulling magnet positioned in the housing and constructed and arranged to produce a nulling magnetic field that reduces the strength of the transducer magnetic field at the magnetic field sensor.

Abstract: Technology described in this document can be embodied in a method that includes receiving a first input signal representing audio captured by a first sensor disposed in a signal path of an active noise reduction (ANR) device, and receiving a second input signal representing audio captured by a second sensor disposed in the signal path of the ANR device. The method also includes processing, by at least one compensator, the first input signal and the second input signal to generate a drive signal for an acoustic transducer of the ANR device. A gain applied to the signal path is at least 3 dB less relative to an ANR signal path having a single sensor.

Abstract: A headphone includes an electro-acoustic transducer for creating audio output, the electro-acoustic transducer comprising a transducer magnet that produces a transducer magnetic field having a magnetic field strength, a housing constructed and arranged to be positioned at an ear of a wearer so as to direct the audio output at the ear canal of the ear, a magnetic field sensor positioned in the housing and constructed and arranged to sense the Earth's magnetic field, and a nulling magnet positioned in the housing and constructed and arranged to produce a nulling magnetic field that reduces the strength of the transducer magnetic field at the magnetic field sensor.

Abstract: This document describes a method that includes receiving an input signal representing audio captured by a sensor disposed in an active noise reduction (ANR) device, determining, by one or more processing devices, that the ANR device is operating in a first operational mode, and in response, applying a first gain to the input signal to generate a first amplified input signal. The method also includes determining, by the one or more processing devices, that the ANR device is operating in a second operational mode different from the first operational mode, and in response, applying a second gain to the input signal to generate a second amplified input signal, wherein the second gain is different from the first gain. The method further includes processing the first or second amplified input signal to generate an output signal, and generating, by an acoustic transducer, an audio output based on the output signal.

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: A headphone includes an electro-acoustic transducer for creating audio output, the electro-acoustic transducer comprising a transducer magnet that produces a transducer magnetic field having a magnetic field strength, a housing constructed and arranged to be positioned at an ear of a wearer so as to direct the audio output at the ear canal of the ear, a magnetic field sensor positioned in the housing and constructed and arranged to sense the Earth's magnetic field, and a nulling magnet positioned in the housing and constructed and arranged to produce a nulling magnetic field that reduces the strength of the transducer magnetic field at the magnetic field sensor.

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: 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: A method of transferring audio signals from an analog audio source to an audio sink, where the audio sink has a multiple-pin connector. A cable is coupled to the audio source and to the multiple-pin connector of the audio sink, where the cable is constructed and arranged to carry audio signals. The audio sink detects a return signal provided to the audio sink over the cable, where the audio sink is configured to interpret the receipt of a return signal as indicating that an audio source is operably connected to the audio sink by the cable. Responsive to this detecting, the audio sink receives audio signals from the audio source over the cable.

Abstract: A headphone includes an electro-acoustic transducer for creating audio output, the electro-acoustic transducer comprising a transducer magnet that produces a transducer magnetic field having a magnetic field strength, structure that is constructed and arranged to be positioned so as to direct the audio output at the ear canal of the ear of a wearer of the headphone, a magnetic field sensor constructed and arranged to sense the Earth's magnetic field, and a nulling magnet constructed and arranged to produce a nulling magnetic field that reduces the strength of the transducer magnetic field at the magnetic field sensor.

Abstract: A headphone includes an electro-acoustic transducer for creating audio output, the electro-acoustic transducer comprising a transducer magnet that produces a transducer magnetic field having a magnetic field strength, structure that is constructed and arranged to be positioned so as to direct the audio output at the ear canal of the ear of a wearer of the headphone, a magnetic field sensor constructed and arranged to sense the Earth's magnetic field, and a nulling magnet constructed and arranged to produce a nulling magnetic field that reduces the strength of the transducer magnetic field at the magnetic field sensor.

Abstract: A headphone includes an electro-acoustic transducer for creating audio output, the electro-acoustic transducer comprising a transducer magnet that produces a transducer magnetic field having a magnetic field strength, a housing constructed and arranged to be positioned at an ear of a wearer so as to direct the audio output at the ear canal of the ear, a magnetic field sensor positioned in the housing and constructed and arranged to sense the Earth's magnetic field, and a nulling magnet positioned in the housing and constructed and arranged to produce a nulling magnetic field that reduces the strength of the transducer magnetic field at the magnetic field sensor.

Abstract: A method of transferring audio signals from an analog audio source to an audio sink, where the audio sink has a multiple-pin connector. A cable is coupled to the audio source and to the multiple-pin connector of the audio sink, where the cable is constructed and arranged to carry audio signals. The audio sink detects a return signal provided to the audio sink over the cable, where the audio sink is configured to interpret the receipt of a return signal as indicating that an audio source is operably connected to the audio sink by the cable. Responsive to this detecting, the audio sink receives audio signals from the audio source over the cable.

Abstract: A headphone includes an electro-acoustic transducer for creating audio output, the electro-acoustic transducer comprising a transducer magnet that produces a transducer magnetic field having a magnetic field strength, a housing constructed and arranged to be positioned at an ear of a wearer so as to direct the audio output at the ear canal of the ear, a magnetic field sensor positioned in the housing and constructed and arranged to sense the Earth's magnetic field, and a nulling magnet positioned in the housing and constructed and arranged to produce a nulling magnetic field that reduces the strength of the transducer magnetic field at the magnetic field sensor.

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.