Bose Corporation

Anand Parthasarathi

Eric Matthew Wallace

Michael J Monahan

Ryan Christopher Silvestri

Kevin Paul Annunziato

Jason Harlow

Pericles Nicholas Bakalos

Daniel M Gauger, Jr

John Allen Rule

Lei Cheng

Matthew Ryan Hicks

Jr Daniel M Gauger

Pericles Bakalos

An active noise reduction earphone includes structure for positioning and retaining the earphone in the ear of a user and, active noise reduction circuitry including an acoustic driver with a nominal diameter greater than 10 mm oriented so that a line parallel to, or coincident with, an axis of the acoustic driver and that intersects a centerline of the nozzle intersects the centerline of the nozzle at angle &#x3d1;&#x3e;&#xb1;30 degrees. A microphone is positioned adjacent an edge of the acoustic driver. The earphone is configured so that a portion of the acoustic driver is within the concha and another portion of the acoustic driver is outside the concha.

In-ear active noise reduction earphone

An active noise reduction (ANR) earphone system includes a feedback microphone for detecting noise, feedback circuitry, responsive to the feedback microphone, for applying a digital filter Kto an output of the feedback microphone to produce an antinoise signal, an electroacoustic driver for transducing the antinoise signal into acoustic energy, a housing supporting the feedback microphone and the driver near the entrance to the ear canal, and an ear tip for coupling the housing to the external anatomical structures of a first ear of a user and positioning the housing to provide a consistent acoustic coupling of the feedback microphone and the driver to the ear canal of the first ear. The acoustic coupling includes a tube of air defined by the combination of the housing and ear tip, having a length L and effective cross-sectional area A such that the ratio L/A is less than 0.6 m.

An active noise reduction earphone. The earphone includes structure for positioning and retaining the earphone in the ear of a user without a headband, active noise reduction circuitry including an acoustic driver with a nominal diameter greater than 10 mm oriented so that a line parallel to, or coincident with, an axis of the acoustic driver and that intersects a centerline of the nozzle intersects the centerline of the nozzle at angle &#x3b8;&#x3e;&#xb1;30 degrees. A microphone is positioned adjacent an edge of the acoustic driver. The earphone is configured so that a portion of the acoustic driver is within the concha of a user and another portion of the acoustic driver is outside the concha of the user when the earphone is in position. An opening coupling the nozzle to the environment includes impedance providing structure in the opening.

In one aspect, in general, an active noise reduction system detects actual or potential instability by detecting characteristics of the system related to potential or actual unstable behavior (e.g., oscillation) and adapts system characteristics to mitigate such instability. In some examples, the system adapts to variation in characteristics of an acoustic component of a feedback path that has or may induce unstable behavior to improve a user's acoustic experience.

Instability detection and avoidance in a feedback system

In an aspect, the invention features an active noise reduction device including an electronic signal processing circuit. The electronic signal processing circuit includes a first input for accepting a first signal, a second input for accepting a second signal, an output for providing a third signal, a feed-forward path from the first input to the output, and a feed-forward controller for determining the control parameter by calculating a control signal using the first signal and the second signal and then using the control signal to determine the control parameter. The feed-forward path includes a fixed compensation linear filter and a variable compensation filter having an input for receiving a control parameter that applies a selected linear filter from a family of linear filters that vary in both gain and spectral shape and are selectable by the control parameter.

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Ashland, MA, United States of America

Anand Parthasarathi