In-the-ear automatic-noise-reduction devices, assemblies, components, and methods
First Claim
1. An in-the-ear automatic noise reduction (ANR) device assembly comprising:
- a housing containing an ANR driver, with the driver dividing an interior of the housing into a back cavity and a front cavity;
an ear-insertion port having a first end acoustically coupled to the front cavity and a second end configured for insertion within the ear canal of a user, wherein the ear insertion port has an effective acoustic mass in a range of 2000 to 2500 kq/M4, with M defined as pL/A, where p is density of air, L is the effective length of the ear-insertion port, and A is the open cross-sectional area of the ear-insertion port; and
an ANR feedback microphone positioned within the ear-insertion port.
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Accused Products
Abstract
Automatic noise-reduction (ANR) headsets include circuitry that cancels or suppress undesired noises. Recent years have seen the emergence of in-the-ear (ITE) earphones that incorporate ANR technology; however, designing them to function well usually entails many design tradeoffs, such as using larger ear nozzles that are uncomfortable to obtain desired noise reduction or that require added structures to hold the earphones to a user ear. To avoid these tradeoffs, the present inventors devised, among other things, an exemplary ITE ANR earphone that places its error measurement microphone in the ear nozzle that connects the driver front acoustic volume to a user ear canal. This placement allows use of a narrower more comfortable ear nozzle without compromising noise reduction and without requiring added holding structures. Moreover, the narrower ear nozzle also lowers the likelihood that the ANR circuitry will become unstable and produce undesirable noise.
27 Citations
19 Claims
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1. An in-the-ear automatic noise reduction (ANR) device assembly comprising:
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a housing containing an ANR driver, with the driver dividing an interior of the housing into a back cavity and a front cavity; an ear-insertion port having a first end acoustically coupled to the front cavity and a second end configured for insertion within the ear canal of a user, wherein the ear insertion port has an effective acoustic mass in a range of 2000 to 2500 kq/M4, with M defined as pL/A, where p is density of air, L is the effective length of the ear-insertion port, and A is the open cross-sectional area of the ear-insertion port; and an ANR feedback microphone positioned within the ear-insertion port. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An in-the-ear automatic noise reduction (ANR) device assembly comprising:
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a housing containing an ANR driver, with the driver dividing an interior of the housing into a back cavity and a front cavity; an ear-insertion port having a first end acoustically coupled to the front cavity and a second end configured for insertion within the ear canal of a user, with the second end including a conformal adapter tip configured to conform to the ear canal of a user and retain the housing adjacent the ear of a user, wherein the ear-insertion port has an effective acoustic mass in a range of 2000 to 2500 kq/M4, with M defined as pL/A, where p is density of air, L is the effective length of the ear-insertion port, and A is the open cross-sectional area of the ear-insertion port; and an ANR feedback microphone positioned within the ear-insertion port; and
ANR processing circuitry coupled to the ANR driver and ANR feedback port. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A method of operating an in-the-ear (ITE) automatic noise reduction (ANR) earphone having an ear-insertion port, the method comprising:
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providing an ambient noise microphone coupled to ANR processing circuitry; providing a feedback error microphone within the ear-insertion port, with the feedback error microphone coupled to the ANR processing circuitry; wherein the ear-insertion port has an effective acoustic mass in a range of 2000 to 2500 kq/M4, with M defined as pL/A, where p is density of air, L is the effective length of the ear-insertion port, and A is the open cross-sectional area of the ear-insertion port; and changing filter characteristics of a filter coupled to the feedforward microphone in response to at least one transfer function estimated using at least one of the ambient noise and feedback error microphones. - View Dependent Claims (18, 19)
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Specification