DIGITAL HIGH FREQUENCY PHASE COMPENSATION
First Claim
1. A method of implementing a high-frequency phase compensation transform to enable increasing at least one of a magnitude and an upper frequency of a range of frequencies at which ANR is provided in a personal ANR device, the method comprising:
- programming a digital filter having at least one tap with at least one coefficient to cause the digital filter to employ the at least one tap to introduce at least one zero to introduce a positive phase; and
selecting the at least one coefficient to cause the addition of a gain that increases with frequency within a portion of a range of audible frequencies and that flattens in a range of frequencies above the range of audible frequencies.
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Accused Products
Abstract
In an ANR circuit of a personal ANR device, a digital filter is structured to introduce one or more zeros to add gain to introduce positive phase in the provision of feedback-based ANR, wherein the gain follows a frequency-dependent “ski-slope” gain curve with little gain added at lower audible frequencies, with increasing gain that increases with frequency added at higher audible frequencies, and with the increasing gain flattening at frequencies above audible frequencies.
170 Citations
16 Claims
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1. A method of implementing a high-frequency phase compensation transform to enable increasing at least one of a magnitude and an upper frequency of a range of frequencies at which ANR is provided in a personal ANR device, the method comprising:
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programming a digital filter having at least one tap with at least one coefficient to cause the digital filter to employ the at least one tap to introduce at least one zero to introduce a positive phase; and selecting the at least one coefficient to cause the addition of a gain that increases with frequency within a portion of a range of audible frequencies and that flattens in a range of frequencies above the range of audible frequencies. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An ANR circuit structured to provide at least one of feedforward-based ANR and feedback-based ANR, the ANR circuit comprising:
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at least a first digital filter positioned along a pathway defined in the ANR circuit and configured with at least a first coefficient to implement a first transform to generate digital data representing an anti-noise sound; at least a second digital filter positioned along the pathway and configured with at least a second coefficient to introduce at least one zero to implement high-frequency phase compensation transform to introduce a positive phase in the pathway to increase at least one of a magnitude and an upper frequency of a range of frequencies at which the at least one of the feedforward-based ANR and the feedback-based ANR is provided, wherein; introducing the at least one zero adds gain increasing with frequency at least partly within a range of audible frequencies; and the gain flattens in a range of frequencies above the range of audible frequencies. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A personal ANR device to provide at least one of feedforward-based ANR and feedback-based ANR to an ear of a user, the personal ANR device comprising:
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a casing defining a cavity to be acoustically coupled to an ear canal of an ear of the user at a time when the casing is in position adjacent the ear; an acoustic driver disposed within the casing to acoustically output anti-noise sounds into the cavity as part of the provision of the at least one of the feedforward-based ANR and the feedback-based ANR; an ANR circuit coupled to generate the anti-noise sounds from noise reference sounds the acoustic driver to drive the acoustic driver with an analog signal to cause the acoustic driver to acoustically output the anti-noise sounds; at least one digital filter incorporated into the ANR circuit; and at least one tap incorporated into the digital filter and configured with at least one coefficient to introduce at least one zero to implement high-frequency phase compensation transform to introduce a positive phase in the generation of the anti-noise sounds to increase at least one of a magnitude and an upper frequency of a range of frequencies at which the at least one of the feedforward-based ANR and the feedback-based ANR is provided, wherein; introducing the at least one zero adds gain increasing with frequency at least partly within a range of audible frequencies; and the gain flattens in a range of frequencies above the range of audible frequencies. - View Dependent Claims (14, 15, 16)
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Specification