Systems and methods for hybrid adaptive noise cancellation
First Claim
1. A personal audio device comprising:
- a personal audio device housing;
a transducer coupled to the housing for reproducing an audio signal including both a source audio signal for playback to a listener and an anti-noise signal for countering the effects of ambient audio sounds in an acoustic output of the transducer;
a reference microphone coupled to the housing for providing a reference microphone signal indicative of the ambient audio sounds;
an error microphone coupled to the housing in proximity to the transducer for providing an error microphone signal indicative of the acoustic output of the transducer and the ambient audio sounds at the transducer; and
a processing circuit that implements;
a feedback filter having a response that generates a feedback anti-noise signal component from a playback corrected error, the playback corrected error based on a difference between the error microphone signal and a secondary path estimate, and wherein the anti-noise signal comprises at least the feedback anti-noise signal component;
a secondary path estimate filter configured to model an electro-acoustic path of the source audio signal and have a response that generates a secondary path estimate from the source audio signal;
a secondary coefficient control block that shapes the response of the secondary path estimate adaptive filter in conformity with the source audio signal and the playback corrected error by adapting the response of the secondary path estimate adaptive filter to minimize the playback corrected error; and
a feedforward filter having a response that generates a feedforward anti-noise signal component from the reference microphone signal; and
wherein;
the anti-noise signal comprises at least the feedback anti-noise signal component and the feedforward anti-noise signal component; and
the processing circuit modifies processing of the feedforward filter responsive to a disturbance in the reference microphone signal, wherein modifying processing of the feedforward filter comprises one of disabling the feedforward filter from generating the feedforward anti-noise signal component, disabling adaptation of the feedforward filter, and resetting adaptation of the feedforward filter.
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Abstract
In accordance with methods and systems of the present disclosure, a processing circuit may implement a feedback filter having a response that generates a feedback anti-noise signal component from a playback corrected error, the playback corrected error based on a difference between an error microphone signal and a secondary path estimate, and wherein the anti-noise signal comprises at least the feedback anti-noise signal component, a secondary path estimate filter configured to model an electro-acoustic path of the source audio signal and have a response that generates a secondary path estimate from the source audio signal, and a secondary coefficient control block that shapes the response of the secondary path estimate adaptive filter in conformity with a source audio signal and the playback corrected error by adapting the response of the secondary path estimate adaptive filter to minimize the playback corrected error.
286 Citations
87 Claims
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1. A personal audio device comprising:
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a personal audio device housing; a transducer coupled to the housing for reproducing an audio signal including both a source audio signal for playback to a listener and an anti-noise signal for countering the effects of ambient audio sounds in an acoustic output of the transducer; a reference microphone coupled to the housing for providing a reference microphone signal indicative of the ambient audio sounds; an error microphone coupled to the housing in proximity to the transducer for providing an error microphone signal indicative of the acoustic output of the transducer and the ambient audio sounds at the transducer; and a processing circuit that implements; a feedback filter having a response that generates a feedback anti-noise signal component from a playback corrected error, the playback corrected error based on a difference between the error microphone signal and a secondary path estimate, and wherein the anti-noise signal comprises at least the feedback anti-noise signal component; a secondary path estimate filter configured to model an electro-acoustic path of the source audio signal and have a response that generates a secondary path estimate from the source audio signal; a secondary coefficient control block that shapes the response of the secondary path estimate adaptive filter in conformity with the source audio signal and the playback corrected error by adapting the response of the secondary path estimate adaptive filter to minimize the playback corrected error; and a feedforward filter having a response that generates a feedforward anti-noise signal component from the reference microphone signal; and wherein; the anti-noise signal comprises at least the feedback anti-noise signal component and the feedforward anti-noise signal component; and the processing circuit modifies processing of the feedforward filter responsive to a disturbance in the reference microphone signal, wherein modifying processing of the feedforward filter comprises one of disabling the feedforward filter from generating the feedforward anti-noise signal component, disabling adaptation of the feedforward filter, and resetting adaptation of the feedforward filter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of for canceling ambient audio sounds in the proximity of a transducer of a personal audio device, the method comprising:
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receiving a reference microphone signal indicative of the ambient audio sounds; receiving an error microphone signal indicative of the output of the transducer and the ambient audio sounds at the transducer; generating a source audio signal for playback to a listener; generating a feedback anti-noise signal component from a playback corrected error, the playback corrected error based on a difference between the error microphone signal and a secondary path estimate, countering the effects of ambient audio sounds at an acoustic output of the transducer, wherein an anti-noise signal comprises at least the feedback anti-noise signal component; adaptively generating the secondary path estimate from the source audio signal by filtering the source audio signal with a secondary path estimate adaptive filter modeling an electro-acoustic path of the source audio signal and adapting the response of the secondary path estimate adaptive filter to minimize the playback corrected error; combining the anti-noise signal with the source audio signal to generate an audio signal provided to the transducer; generating a feedforward anti-noise signal component, from a result of the measuring with the reference microphone, countering the effects of ambient audio sounds at an acoustic output of the transducer by filtering an output of the reference microphone, wherein the anti-noise signal comprises at least the feedback anti-noise signal component and the feedforward anti-noise signal component; and modifying processing of the feedforward anti-noise signal component responsive to a disturbance in the reference microphone signal, wherein modifying processing comprises one of disabling generation of the feedforward-anti-noise signal component, disabling adaptation of the feedforward-anti-noise signal component, and resetting the feedforward-anti-noise signal component. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. An integrated circuit for implementing at least a portion of a personal audio device, comprising:
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an output for providing a signal to a transducer including both a source audio signal for playback to a listener and an anti-noise signal for countering the effect of ambient audio sounds in an acoustic output of the transducer; a reference microphone input for receiving a reference microphone signal indicative of the ambient audio sounds; an error microphone input for receiving an error microphone signal indicative of the output of the transducer and the ambient audio sounds at the transducer; and a processing circuit that implements; a feedback filter having a response that generates a feedback anti-noise signal component from a playback corrected error, the playback corrected error based on a difference between the error microphone signal and a secondary path estimate, and wherein the anti-noise signal comprises at least the feedback anti-noise signal component; a secondary path estimate adaptive filter for modeling an electro-acoustic path of the source audio signal having a response that generates the secondary path estimate from the source audio signal; a secondary coefficient control block that shapes the response of the secondary path estimate adaptive filter in conformity with the source audio signal and the playback corrected error by adapting the response of the secondary path estimate adaptive filter to minimize the playback corrected error; and a feedforward filter having a response that generates a feedforward anti-noise signal component from the reference microphone signal; and wherein; the anti-noise signal comprises at least the feedback anti-noise signal component and the feedforward anti-noise signal component; and the processing circuit modifies processing of the feedforward filter responsive to a disturbance in the reference microphone signal, wherein modifying processing of the feedforward filter comprises one of disabling the feedforward filter from generating the feedforward anti-noise signal component, disabling adaptation of the feedforward filter, and resetting adaptation of the feedforward filter. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. A personal audio device comprising:
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a personal audio device housing; a transducer coupled to the housing for reproducing an audio signal including both a source audio signal for playback to a listener and an anti-noise signal for countering the effects of ambient audio sounds in an acoustic output of the transducer; an error microphone coupled to the housing in proximity to the transducer for providing an error microphone signal indicative of the acoustic output of the transducer and the ambient audio sounds at the transducer; a processing circuit that implements; a feedback filter having a response that generates a feedback anti-noise signal component from a playback corrected error, the playback corrected error based on a difference between the error microphone signal and a secondary path estimate, and wherein the anti-noise signal comprises at least the feedback anti-noise signal component; a secondary path estimate filter configured to model an electro-acoustic path of the source audio signal and have a response that generates a secondary path estimate from the source audio signal; a programmable feedback gain, wherein an increasing programmable feedback gain increases the feedback anti-noise signal component and a decreasing programmable feedback gain decreases the feedback anti-noise signal component; and a reference microphone coupled to the housing for providing a reference microphone signal indicative of the ambient audio sounds; wherein; the processing circuit further implements a feedforward filter having a response that generates a feedforward anti-noise signal component from the reference microphone signal the anti-noise signal comprises at least the feedback anti-noise signal component and the feedforward anti-noise signal component; and the processing circuit modifies processing of the feedforward filter responsive to a disturbance in the reference microphone signal, wherein modifying processing of the feedforward filter comprises one of disabling the feedforward filter from generating the feedforward anti-noise signal component, disabling adaptation of the feedforward filter, and resetting adaptation of the feedforward filter. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38)
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39. A method of for canceling ambient audio sounds in the proximity of a transducer of a personal audio device, the method comprising:
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receiving an error microphone signal indicative of the output of the transducer and the ambient audio sounds at the transducer; generating a source audio signal for playback to a listener; generating a feedback anti-noise signal component from a playback corrected error, the playback corrected error based on a difference between the error microphone signal and a secondary path estimate, countering the effects of ambient audio sounds at an acoustic output of the transducer, wherein an anti-noise signal comprises at least the feedback anti-noise signal component; generating the secondary path estimate from the source audio signal by filtering the source audio signal with a secondary path estimate filter modeling an electro-acoustic path of the source audio signal; applying a programmable feedback gain to a path of the feedback anti-noise signal component, wherein an increasing programmable feedback gain increases the feedback anti-noise signal component and a decreasing programmable feedback gain decreases the feedback anti-noise signal component; and combining the anti-noise signal with a source audio signal to generate an audio signal provided to the transducer; receiving a reference microphone signal indicative of the ambient audio sounds; generating a feedforward anti-noise signal component, from a result of the measuring with the reference microphone, countering the effects of ambient audio sounds at an acoustic output of the transducer by filtering an output of the reference microphone, wherein the anti-noise signal comprises at least the feedback anti-noise signal component and the feedforward anti-noise signal component; and modifying processing of the feedforward anti-noise signal component responsive to a disturbance in the reference microphone signal, wherein modifying processing comprises one of disabling generation of the feedforward-anti-noise signal component, disabling adaptation of the feedforward-anti-noise signal component, and resetting the feedforward-anti-noise signal component. - View Dependent Claims (40, 41, 42, 43, 44, 45, 46)
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47. An integrated circuit for implementing at least a portion of a personal audio device, comprising:
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an output for providing a signal to a transducer including both a source audio signal for playback to a listener and an anti-noise signal for countering the effect of ambient audio sounds in an acoustic output of the transducer; an error microphone input for receiving an error microphone signal indicative of the output of the transducer and the ambient audio sounds at the transducer; and a processing circuit that implements; a feedback filter having a response that generates a feedback anti-noise signal component from a playback corrected error, the playback corrected error based on a difference between the error microphone signal and a secondary path estimate, and wherein the anti-noise signal comprises at least the feedback anti-noise signal component; a secondary path estimate filter configured to model an electro-acoustic path of the source audio signal and have a response that generates a secondary path estimate from the source audio signal; and a programmable feedback gain, wherein an increasing programmable feedback gain increases the feedback anti-noise signal component and a decreasing programmable feedback gain decreases the feedback anti-noise signal component; and a reference microphone input for receiving a reference microphone signal indicative of the ambient audio sounds; wherein; the processing circuit further implements a feedforward filter having a response that generates a feedforward anti-noise signal component from the reference microphone signal the anti-noise signal comprises at least the feedback anti-noise signal component and the feedforward anti-noise signal component; and the processing circuit modifies processing of the feedforward filter responsive to a disturbance in the reference microphone signal, wherein modifying processing of the feedforward filter comprises one of disabling the feedforward filter from generating the feedforward anti-noise signal component, disabling adaptation of the feedforward filter, and resetting adaptation of the feedforward filter. - View Dependent Claims (48, 49, 50, 51, 52, 53, 54, 55)
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56. A personal audio device comprising:
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a personal audio device housing; a transducer coupled to the housing for reproducing an audio signal including both a source audio signal for playback to a listener and an anti-noise signal for countering the effects of ambient audio sounds in an acoustic output of the transducer; a reference microphone coupled to the housing for providing a reference microphone signal indicative of the ambient audio sounds; an error microphone coupled to the housing in proximity to the transducer for providing an error microphone signal indicative of the acoustic output of the transducer and the ambient audio sounds at the transducer; and a processing circuit that implements; a feedback filter having a response that generates a feedback anti-noise signal component from a playback corrected error, the playback corrected error based on a difference between the error microphone signal and a secondary path estimate; a feedforward filter having a response that generates a feedforward anti-noise signal component from the reference microphone signal, wherein the anti-noise signal comprises at least the feedback anti-noise signal component and the feedforward anti-noise signal component, wherein the feedforward filter is configured to be disabled from generating the feedforward anti-noise signal component responsive to a disturbance in the reference microphone signal; and a secondary path estimate filter configured to model an electro-acoustic path of the source audio signal and have a response that generates a secondary path estimate from the source audio signal. - View Dependent Claims (57, 58, 59, 60, 61, 62, 63, 64, 65, 66)
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67. A method for canceling ambient audio sounds in the proximity of a transducer of a personal audio device, the method comprising:
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receiving a reference microphone signal indicative of the ambient audio sounds; receiving an error microphone signal indicative of the output of the transducer and the ambient audio sounds at the transducer; generating a source audio signal for playback to a listener; generating a feedback anti-noise signal component from a playback corrected error, the playback corrected error based on a difference between the error microphone signal and a secondary path estimate, countering the effects of ambient audio sounds at an acoustic output of the transducer, wherein an anti-noise signal comprises at least the feedback anti-noise signal component; generating the secondary path estimate from the source audio signal by filtering the source audio signal with a secondary path estimate filter modeling an electro-acoustic path of the source audio signal; generating a feedforward anti-noise signal component, from a result of the measuring with the reference microphone, countering the effects of ambient audio sounds at an acoustic output of the transducer by filtering with a feedforward filter an output of the reference microphone, wherein the anti-noise signal comprises at least the feedback anti-noise signal component and the feedforward anti-noise signal component; disabling the feedforward filter from generating the feedforward anti-noise signal component responsive to a disturbance in the reference microphone signal; and combining the anti-noise signal with a source audio signal to generate an audio signal provided to the transducer. - View Dependent Claims (68, 69, 70, 71, 72, 73, 74, 75, 76)
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77. An integrated circuit for implementing at least a portion of a personal audio device, comprising:
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an output for providing a signal to a transducer including both a source audio signal for playback to a listener and an anti-noise signal for countering the effect of ambient audio sounds in an acoustic output of the transducer; a reference microphone input for receiving a reference microphone signal indicative of the ambient audio sounds; an error microphone input for receiving an error microphone signal indicative of the output of the transducer and the ambient audio sounds at the transducer; and a processing circuit that implements; a feedback filter having a response that generates a feedback anti-noise signal component from a playback corrected error, the playback corrected error based on a difference between the error microphone signal and a secondary path estimate; a feedforward filter having a response that generates a feedforward anti-noise signal component from the reference microphone signal, wherein the anti-noise signal comprises at least the feedback anti-noise signal component and the feedforward anti-noise signal component, wherein the feedforward filter is configured to be disabled from generating the feedforward anti-noise signal component responsive to a disturbance in the reference microphone signal; and a secondary path estimate filter configured to model an electro-acoustic path of the source audio signal and have a response that generates a secondary path estimate from the source audio signal. - View Dependent Claims (78, 79, 80, 81, 82, 83, 84, 85, 86, 87)
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Specification