Bose Corporation

Emery M Ku

David R Minich

Lei Cheng

Ole Mattis Nielsen

Cedrik Bacon

Andrew D Munro

Paraskevas Argyropoulos

Richard L Pyatt

David J Warkentin

Douglas George Morton

Michelle Gelberger

Alexia Delhoume

James P Mulvey

Technology described in this document can be embodied in an earpiece of an active noise reduction (ANR) device. The earpiece includes a plurality of microphones, wherein each of the plurality of microphones is usable for capturing ambient audio to generate input signals for both an ANR mode of operation and a hear-through mode of operation of the ANR device. The earpiece further includes a controller configured to: process a first subset of microphones from the plurality of microphones to generate input signals for the ANR mode of operation and process a second subset of microphones from the plurality of microphones to generate input signals for the hear-through mode of operation. The second subset of microphones excludes a first microphone from the plurality of microphones located closest to a noise pathway of the earpiece.

Dynamic control of multiple feedforward microphones in active noise reduction devices

A method performed by an audio output device is provided for detecting instabilities and taking mitigating actions. Specifically, an A-weighted dBA level of a raw feedback signal exceeding a threshold level trigger, at least, muting the driver. The described methods apply to detecting instabilities across a broad frequency spectrum.

Broad spectrum instability detection and mitigation

An active noise reduction earbud includes a housing and a first feedforward microphone disposed in the housing. A first sound inlet opening extends through the housing and is configured to conduct external sound to the first feedforward microphone. The first sound inlet opening is configured to sit within a concha cavum of a user's ear and faces toward an auricle of the user's ear when the earbud is worn.

Active noise reduction earbud

A method and system directed to controlling audio devices with active noise reduction. The system detects a first instability condition in a first headphone based on one or more parameters; alters a parameter of the one or more parameters; and detects a second audio instability condition in the first headphone based on the altered parameter of the one or more parameters. The first and second audio instability conditions are related to audio feedback.

Synchronization of instability mitigation in audio devices

An apparatus includes a noise reduction headphone comprising one or more microphones and an acoustic transducer, the one or more microphones configured to generate an input signal; and a controller comprising one or more processing devices, the controller configured to: process the input signal through one or more noise reduction filters to generate a noise-reduction signal, compare the input signal to an estimate of ambient noise to determine if the energy of the input signal is greater than the estimate of ambient noise, wherein if the energy of the input signal is greater than the estimate of ambient noise by a predetermined amount, a change in the noise reduction signal is suppressed; and generate an output signal, the output signal comprising, at least in part, the noise-reduction signal, wherein the acoustic transducer is configured to produce an acoustic output in accordance with the output signal.

Active noise reduction with impulse detection and suppression

A method for detecting and mitigating parasitic oscillation in a headphone equipped with an active noise reduction (ANR) system. A fundamental frequency of a microphone signal is determined from a microphone of the ANR system and an amplitude of the determined fundamental frequency is compared to a threshold level to determine parasitic oscillation. If parasitic oscillation is determined, then the microphone signal is altered to mitigate the parasitic oscillation.

Wearable audio device zero-crossing based parasitic oscillation detection

A method and system directed to controlling Active Noise Reduction (ANR) audio devices with active noise reduction. The system sets one or more ANR parameters of a first and a second wearable audio device to a first ANR state; detects that the first wearable audio device is removed from a first ear of a user; and automatically adjusts the one or more ANR parameters of the second wearable audio device to a second ANR state when the first wearable audio device is removed from the ear of the user, wherein the second ANR state comprises a reduction in a level of ANR compared to the first ANR state.

Active noise reduction audio devices and systems

A method and system directed to controlling audio devices with active noise reduction. The system detects an instability condition in a first headphone; generates one or more control signals to adjust one or more ANR parameters of the first headphone using a first controller, wherein the one or more ANR parameters are adjusted to change the first headphone from a first ANR state to a second ANR state to mitigate the instability condition; and synchronizes the one or more ANR parameters of the first headphone with second headphone. In an example, the system returns the first headphone to the first ANR state after detecting that the first headphone was removed from an ear of a user at the first time and detecting that the first headphone was engaged with the ear at the second time.

A system for detecting parasitic oscillation in a wearable audio device that includes an electro-acoustic transducer that is configured to develop sound for a user, a housing that holds the transducer, at least one of a feedforward microphone that is configured to detect sound outside of the housing and output a feedforward microphone signal and a feedback microphone that is configured to detect sound inside of the housing and output a feedback microphone signal, and an opening in the housing that emits sound pressure from the transducer. The system includes a parasitic oscillation detector that is configured to determine a fundamental frequency of at least one of the feedforward and feedback microphone signals and compare an amplitude of the determined fundamental frequency to a threshold level, to determine parasitic oscillation.

An active noise reduction earbud and method. The earbud includes a housing comprising an outlet portion that defines a sound outlet, wherein the outlet portion is configured to be located in or proximate the external auditory meatus of a user's ear, a first feedforward microphone configured to develop a first input signal, and a first sound inlet opening in the housing and configured to conduct external sound to be sensed by the first feedforward microphone, wherein the first sound inlet opening is proximate the outlet portion.

Technology described in this document can be embodied in an earpiece of an active noise reduction (ANR) device. The earpiece includes a plurality of microphones, wherein each of the plurality of microphones is usable for capturing ambient audio to generate input signals for both an ANR mode of operation and a hear-through mode of operation of the ANR device. The earpiece further includes a controller configured to: process a first subset of microphones from the plurality of microphones to generate input signals for the ANR mode of operation, process a second subset of microphones from the plurality of microphones to generate input signals for the hear-through mode of operation, detect that a particular microphone of the second subset is acoustically coupled to an acoustic transducer of the ANR device in the hear-through mode of operation, and in response to the detection, process the input signals from the second subset of microphones without using input signals from the particular microphone.

A system for detecting feedforward instability in a wearable audio device. The audio device includes an electro-acoustic transducer that is configured to develop sound for a user, a housing that holds the transducer, a feedforward microphone that is configured to detect sound outside of the housing and output a microphone signal, and an opening in the housing that emits sound pressure from the transducer that can reach the microphone. A feedforward instability detector is configured to apply two filters to the microphone signal. A first filter passes more energy in a frequency band than does a second filter, to develop a filtered signal. The filtered signal is compared to the microphone signal outside of the frequency band, to develop a comparison signal that is indicative of feedforward instability in the frequency band.

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Somerville, MA, United States of America

Emery M Ku