Abstract: In one aspect a method that includes receiving an input signal captured by one or more first sensors associated with an active noise reduction (ANR) device, and processing the input signal using a first filter disposed in an ANR signal path to generate a first signal for an acoustic transducer of the ANR device. The input signal is processed in a pass-through signal path disposed in parallel with the ANR signal path to generate a second signal for the acoustic transducer, wherein the pass-through signal path allows a portion of the input signal to pass through to the acoustic transducer in accordance with a variable gain. One or more second sensors detect an existence of a condition likely to cause instability in the pass-through signal path, and in response, the variable gain is adjusted. A driver signal for the acoustic transducer is generated using an output based on the adjusted gain.

Abstract: In one aspect a method that includes receiving an input signal captured by one or more first sensors associated with an active noise reduction (ANR) device, and processing the input signal using a first filter disposed in an ANR signal path to generate a first signal for an acoustic transducer of the ANR device. The input signal is processed in a pass-through signal path disposed in parallel with the ANR signal path to generate a second signal for the acoustic transducer, wherein the pass-through signal path allows a portion of the input signal to pass through to the acoustic transducer in accordance with a variable gain. One or more second sensors detect an existence of a condition likely to cause instability in the pass-through signal path, and in response, the variable gain is adjusted. A driver signal for the acoustic transducer is generated using an output based on the adjusted gain.

Abstract: In one aspect a method that includes receiving an input signal captured by one or more first sensors associated with an active noise reduction (ANR) device, and processing the input signal using a first filter disposed in an ANR signal path to generate a first signal for an acoustic transducer of the ANR device. The input signal is processed in a pass-through signal path disposed in parallel with the ANR signal path to generate a second signal for the acoustic transducer, wherein the pass-through signal path allows a portion of the input signal to pass through to the acoustic transducer in accordance with a variable gain. One or more second sensors detect an existence of a condition likely to cause instability in the pass-through signal path, and in response, the variable gain is adjusted. A driver signal for the acoustic transducer is generated using an output based on the adjusted gain.

Abstract: In one aspect a method that includes receiving an input signal captured by one or more first sensors associated with an active noise reduction (ANR) device, and processing the input signal using a first filter disposed in an ANR signal path to generate a first signal for an acoustic transducer of the ANR device. The input signal is processed in a pass-through signal path disposed in parallel with the ANR signal path to generate a second signal for the acoustic transducer, wherein the pass-through signal path allows a portion of the input signal to pass through to the acoustic transducer in accordance with a variable gain. One or more second sensors detect an existence of a condition likely to cause instability in the pass-through signal path, and in response, the variable gain is adjusted. A driver signal for the acoustic transducer is generated using an output based on the adjusted gain.

Abstract: In one aspect a method that includes receiving an input signal captured by one or more first sensors associated with an active noise reduction (ANR) device, and processing the input signal using a first filter disposed in an ANR signal path to generate a first signal for an acoustic transducer of the ANR device. The input signal is processed in a pass-through signal path disposed in parallel with the ANR signal path to generate a second signal for the acoustic transducer, wherein the pass-through signal path allows a portion of the input signal to pass through to the acoustic transducer in accordance with a variable gain. One or more second sensors detect an existence of a condition likely to cause instability in the pass-through signal path, and in response, the variable gain is adjusted. A driver signal for the acoustic transducer is generated using an output based on the adjusted gain.

Abstract: In one aspect a method that includes receiving an input signal captured by one or more first sensors associated with an active noise reduction (ANR) device, and processing the input signal using a first filter disposed in an ANR signal path to generate a first signal for an acoustic transducer of the ANR device. The input signal is processed in a pass-through signal path disposed in parallel with the ANR signal path to generate a second signal for the acoustic transducer, wherein the pass-through signal path allows a portion of the input signal to pass through to the acoustic transducer in accordance with a variable gain. One or more second sensors detect an existence of a condition likely to cause instability in the pass-through signal path, and in response, the variable gain is adjusted. A driver signal for the acoustic transducer is generated using an output based on the adjusted gain.

Abstract: In one aspect a method that includes receiving an input signal captured by one or more first sensors associated with an active noise reduction (ANR) device, and processing the input signal using a first filter disposed in an ANR signal path to generate a first signal for an acoustic transducer of the ANR device. The input signal is processed in a pass-through signal path disposed in parallel with the ANR signal path to generate a second signal for the acoustic transducer, wherein the pass-through signal path allows a portion of the input signal to pass through to the acoustic transducer in accordance with a variable gain. One or more second sensors detect an existence of a condition likely to cause instability in the pass-through signal path, and in response, the variable gain is adjusted. A driver signal for the acoustic transducer is generated using an output based on the adjusted gain.

Abstract: Various implementations include wearable audio devices and related methods for controlling such devices. Some approaches include controlling a wearable audio device by: determining a magnitude of an acoustic transfer function based on an electrical signal from an internal microphone and an audio signal from an acoustic transducer at one or more predetermined frequencies; calibrating a proximity sensor; detecting a change in the state of the wearable audio device from one of: off-head to on-head, or on-head to off-head using both the calibrated proximity sensor and the magnitude of the acoustic transfer function; and adjusting at least one function of the wearable audio device in response to detecting the change from the on-head state to the off-head state or detecting the change from the off-head state to the on-head state.

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: Various implementations include wearable audio devices and related methods for controlling such devices. Some approaches include controlling a wearable audio device by: determining a magnitude of an acoustic transfer function based on an electrical signal from an internal microphone and an audio signal from an acoustic transducer at one or more predetermined frequencies; calibrating a proximity sensor; detecting a change in the state of the wearable audio device from one of: off-head to on-head, or on-head to off-head using both the calibrated proximity sensor and the magnitude of the acoustic transfer function; and adjusting at least one function of the wearable audio device in response to detecting the change from the on-head state to the off-head state or detecting the change from the off-head state to the on-head state.

Abstract: Various implementations include printed circuit board mounts and related headphone systems employing such mounts. In one implementation, a mount for a printed circuit board (PCB) includes: a plate for matingly engaging an inner portion of a headphone earcup, the plate including at least one PCB mount for coupling with the PCB; and a coupling element extending from the plate and including at least one coupler for coupling the plate proximate to a spine extending through the inner portion of the headphone earcup.

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: Various implementations include wearable audio devices and related methods for controlling such devices. Some approaches include: detecting a change from an on-head state to an off-head state with a first sensor system; calibrating a second, distinct sensor system after detecting the change from the on-head state to the off-head state; detecting a change from the off-head state to the on-head state using the calibrated second sensor system; and adjusting an operating state of at least one function of the wearable audio device in response to detecting the change from the on-head state to the off-head state or detecting the change from the off-head state to the on-head state.

Abstract: Various implementations include printed circuit board mounts and related headphone systems employing such mounts. In one implementation, a mount for a printed circuit board (PCB) includes: a plate for matingly engaging an inner portion of a headphone earcup, the plate including at least one PCB mount for coupling with the PCB; and a coupling element extending from the plate and including at least one coupler for coupling the plate proximate to a spine extending through the inner portion of the headphone earcup.

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: Stability is provided in an active noise reduction (ANR) headphone by measuring a sound field to generate an input signal, filtering and applying a variable gain to the input signal to produce a first filtered signal using a first filter and a variable gain amplifier in an ANR signal pathway, outputting the filtered signal, and simultaneously with outputting the first filtered signal, sampling a signal at a point in the ANR signal pathway and filtering the sampled signal using a second filter to produce a second filtered signal. The second filtered signal is compared to a threshold, and if the comparison finds that the second filtered signal is greater than the threshold signal, the gain of the variable gain amplifier is changed to attenuate the first filtered signal. The second filter applies different gains, different by at least 10 dB, in different frequency ranges between 10 Hz and 10 kHz.

Abstract: A method of processing a metal component is provided. The method includes laser cladding at least one surface of a metal component to obtain a laser cladded metal component having a predefined hardness. The method further includes heat-treating the laser cladded metal component to reduce the predefined hardness of the laser cladded metal component for performing metal working operations thereon. The method also includes cryogenically hardening the laser cladded metal component after the heat-treatment thereof, to induce the predefined hardness to the laser cladded metal component.

Abstract: A method for manufacturing an article from a metal alloy is described. The method includes supplying the metal alloy into a nozzle of a printing chamber, where temperature of the metal alloy is between a solidus and a liquidus temperature. Further, the method includes depositing the metal alloy in successive layers on a substrate plate, inside the printing machine, using the nozzle. The method also includes controlling movement of at least one of the nozzle and the substrate plate within the printing chamber based on an electronic data source of the article, where the electronic data source includes geometry of the article.

Abstract: A seal ring for a seal assembly includes a body and a seal flange. The body is generally cylindrical and extends along a longitudinal axis between a load end and a seal end. The seal flange is disposed at the seal end of the cylindrical body. The seal flange circumscribes the body and projects radially from the body to a distal perimeter of the seal flange. The seal flange includes a sealing face which is annular and disposed adjacent the distal perimeter. The seal ring is made from an alloy that includes between 8 percent and 13 percent by weight of iron, between 2 percent and 3 percent by weight of silicon, between 13 percent and 14 percent by weight of chromium, and at least 65 percent by weight of nickel.

Abstract: A seal ring for a seal assembly includes a body and a seal flange. The body is generally cylindrical and extends along a longitudinal axis between a load end and a seal end. The seal flange is disposed at the seal end of the cylindrical body. The seal flange circumscribes the body and projects radially from the body to a distal perimeter of the seal flange. The seal flange includes a sealing face which is annular and disposed adjacent the distal perimeter. The seal ring is made from an alloy that includes between 8 percent and 13 percent by weight of iron, between 2 percent and 3 percent by weight of silicon, between 13 percent and 14 percent by weight of chromium, and at least 65 percent by weight of nickel.