Patent Grant
10181315
The present disclosure relates in general to adaptive noise cancellation in connection with an acoustic transducer, and more particularly, multi-mode adaptive cancellation for audio headsets.
Wireless telephones, such as mobile/cellular telephones, cordless telephones, and other consumer audio devices, such as mp3 players, are in widespread use. Performance of such devices with respect to intelligibility can be improved by providing noise canceling using a microphone to measure ambient acoustic events and then using signal processing to insert an anti-noise signal into the output of the device to cancel the ambient acoustic events.
In an adaptive noise cancellation system, it is often desirable for the system to be fully adaptive such that a maximum noise cancellation effect is provided to a user at all times. However, when an adaptive noise cancellation system is adapting, it consumes more power than when it is not adapting. Therefore, it may be desirable to have a system that can determine when adaptation is needed, and only adapt during such times in order to reduce power consumption.
In accordance with the teachings of the present disclosure, certain disadvantages and problems associated with power consumption of an adaptive noise cancellation system may be reduced or eliminated.
In accordance with embodiments of the present disclosure, an integrated circuit for implementing at least a portion of a personal audio device may include an output, an error microphone input, and a processing circuit. The output may be configured to provide an output 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. The error microphone input may be configured to receive an error microphone signal indicative of the output of the transducer and the ambient audio sounds at the transducer. The processing circuit may implement an anti-noise generating filter, a secondary path estimate filter, and a controller. The anti-noise generating filter may have a response that generates the anti-noise signal based at least on the reference microphone signal. The secondary path estimate filter may be 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, wherein at least one of the response of the anti-noise generating filter and the response of the secondary path estimate filter is an adaptive response shaped by an adaptive coefficient control block. The adaptive coefficient control block may include at least one of a filter coefficient control block that shapes the response of the anti-noise generating filter by adapting the response of the anti-noise generating filter to minimize the ambient audio sounds in the error microphone signal and a secondary path estimate coefficient control block that shapes the response of the secondary path estimate filter in conformity with the source audio signal and a playback corrected error by adapting the response of the secondary path estimate filter to minimize the playback corrected error; wherein the playback corrected error is based on a difference between the error microphone signal and the secondary path estimate. The controller may be configured to determine a degree of convergence of the adaptive response, enable adaptation of the adaptive coefficient control block if the degree of convergence of the adaptive response is below a particular threshold, and disable adaptation of the adaptive coefficient control block if the degree of convergence of the adaptive response is above a particular threshold.
In accordance with these and other embodiments of the present disclosure, a method for canceling ambient audio sounds in the proximity of a transducer of a personal audio device may include receiving an error microphone signal indicative of an acoustic output of the transducer and the ambient audio sounds at the transducer. The method may further include adaptively generating an anti-noise signal to reduce the presence of the ambient audio sounds heard by the listener by adapting an adaptive response of an adaptive noise cancellation system to minimize the ambient audio sounds at the acoustic output of the transducer, wherein adaptively generating the anti-noise signal comprises generating the anti-noise signal from based on at least the error microphone signal with an anti-noise generating filter, generating a secondary path estimate from the source audio signal with a secondary path estimate filter for modeling an electro-acoustic path of a source audio signal, and at least one of: (i) adaptively generating the anti-noise signal by shaping a response of the anti-noise generating filter by adapting the response of the anti-noise generating filter to minimize the ambient audio sounds in the error microphone signal, wherein the adaptive response comprises the response of the anti-noise generating filter; and (ii) adaptively generating the secondary path estimate by shaping a response of the secondary path estimate filter in conformity with the source audio signal and a playback corrected error by adapting the response of the secondary path estimate filter to minimize the playback corrected error, wherein the playback corrected error is based on a difference between the error microphone signal and the secondary path estimate, wherein the adaptive response comprises the response of the secondary path estimate filter. The method may additionally include combining the anti-noise signal with a source audio signal to generate an output signal provided to the transducer. The method may further include determining a degree of convergence of the adaptive response, enabling adaptation of the adaptive response if the degree of convergence of the adaptive response is below a particular threshold, and disabling adaptation of the adaptive response if the degree of convergence of the adaptive response is above a particular threshold.
In accordance with these and other embodiments of the present disclosure, a personal audio device may include a transducer and an error microphone. The transducer may be configured to reproduce an output 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. The error microphone may be configured to generate an error microphone signal indicative of the output of the transducer and the ambient audio sounds at the transducer. The processing circuit may implement an anti-noise generating filter, a secondary path estimate filter, and a controller. The anti-noise generating filter may have a response that generates the anti-noise signal based at least on the reference microphone signal. The secondary path estimate filter may be 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, wherein at least one of the response of the anti-noise generating filter and the response of the secondary path estimate filter is an adaptive response shaped by an adaptive coefficient control block. The adaptive coefficient control block may include at least one of a filter coefficient control block that shapes the response of the anti-noise generating filter by adapting the response of the anti-noise generating filter to minimize the ambient audio sounds in the error microphone signal and a secondary path estimate coefficient control block that shapes the response of the secondary path estimate filter in conformity with the source audio signal and a playback corrected error by adapting the response of the secondary path estimate filter to minimize the playback corrected error; wherein the playback corrected error is based on a difference between the error microphone signal and the secondary path estimate. The controller may be configured to determine a degree of convergence of the adaptive response, enable adaptation of the adaptive coefficient control block if the degree of convergence of the adaptive response is below a particular threshold, and disable adaptation of the adaptive coefficient control block if the degree of convergence of the adaptive response is above a particular threshold.
In accordance with these and other embodiments of the present disclosure, an integrated circuit for implementing at least a portion of a personal audio device may include a controller configured to determine a degree of convergence of an adaptive response of an adaptive filter in an adaptive noise cancellation system, enable adaptation of the adaptive response if the degree of convergence of the adaptive response is below a particular threshold, and disable adaptation of the adaptive response if the degree of convergence of the adaptive response is above a particular threshold.
Technical advantages of the present disclosure may be readily apparent to one of ordinary skill in the art from the figures, description and claims included herein. The objects and advantages of the embodiments will be realized and achieved at least by the elements, features, and combinations particularly pointed out in the claims.
It is to be understood that both the foregoing general description and the following detailed description are examples and explanatory and are not restrictive of the claims set forth in this disclosure.
A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein:
The present disclosure encompasses noise canceling techniques and circuits that can be implemented in a personal audio device, such as a wireless telephone. The personal audio device includes an ANC circuit that may measure the ambient acoustic environment and generate a signal that is injected in the speaker (or other transducer) output to cancel ambient acoustic events. A reference microphone may be provided to measure the ambient acoustic environment and an error microphone may be included for controlling the adaptation of the anti-noise signal to cancel the ambient audio sounds and for correcting for the electro-acoustic path from the output of the processing circuit through the transducer.
Referring now to
Wireless telephone 10 may include ANC circuits and features that inject an anti-noise signal into speaker SPKR to improve intelligibility of the distant speech and other audio reproduced by speaker SPKR. A reference microphone R may be provided for measuring the ambient acoustic environment, and may be positioned away from the typical position of a user's mouth, so that the near-end speech may be minimized in the signal produced by reference microphone R. Another microphone, error microphone E, may be provided in order to further improve the ANC operation by providing a measure of the ambient audio combined with the audio reproduced by speaker SPKR close to ear 5, when wireless telephone 10 is in close proximity to ear 5. In other embodiments, additional reference and/or error microphones may be employed. Circuit 14 within wireless telephone 10 may include an audio CODEC integrated circuit (IC) 20 that receives the signals from reference microphone R, near-speech microphone NS, and error microphone E and interfaces with other integrated circuits such as a radio-frequency (RF) integrated circuit 12 having a wireless telephone transceiver. In some embodiments of the disclosure, the circuits and techniques disclosed herein may be incorporated in a single integrated circuit that includes control circuits and other functionality for implementing the entirety of the personal audio device, such as an MP3 player-on-a-chip integrated circuit. In these and other embodiments, the circuits and techniques disclosed herein may be implemented partially or fully in software and/or firmware embodied in computer-readable media and executable by a controller or other processing device.
In general, ANC techniques of the present disclosure measure ambient acoustic events (as opposed to the output of speaker SPKR and/or the near-end speech) impinging on reference microphone R, and by also measuring the same ambient acoustic events impinging on error microphone E, ANC processing circuits of wireless telephone 10 adapt an anti-noise signal generated from the output of reference microphone R to have a characteristic that minimizes the amplitude of the ambient acoustic events at error microphone E. Because acoustic path P(z) extends from reference microphone R to error microphone E, ANC circuits are effectively estimating acoustic path P(z) while removing effects of an electro-acoustic path S(z) that represents the response of the audio output circuits of CODEC IC 20 and the acoustic/electric transfer function of speaker SPKR including the coupling between speaker SPKR and error microphone E in the particular acoustic environment, which may be affected by the proximity and structure of ear 5 and other physical objects and human head structures that may be in proximity to wireless telephone 10, when wireless telephone 10 is not firmly pressed to ear 5. While the illustrated wireless telephone 10 includes a two-microphone ANC system with a third near-speech microphone NS, some aspects of the present invention may be practiced in a system that does not include separate error and reference microphones, or a wireless telephone that uses near-speech microphone NS to perform the function of the reference microphone R. Also, in personal audio devices designed only for audio playback, near-speech microphone NS will generally not be included, and the near-speech signal paths in the circuits described in further detail below may be omitted, without changing the scope of the disclosure, other than to limit the options provided for input to the microphone.
Referring now to
Combox 16 or another portion of headphone assembly 13 may have a near-speech microphone NS to capture near-end speech in addition to or in lieu of near-speech microphone NS of wireless telephone 10. In addition, each headphone 18A, 18B may include a transducer such as speaker SPKR that reproduces distant speech received by wireless telephone 10, along with other local audio events such as ringtones, stored audio program material, injection of near-end speech (i.e., the speech of the user of wireless telephone 10) to provide a balanced conversational perception, and other audio that requires reproduction by wireless telephone 10, such as sources from webpages or other network communications received by wireless telephone 10 and audio indications such as a low battery indication and other system event notifications. Each headphone 18A, 18B may include a reference microphone R for measuring the ambient acoustic environment and an error microphone E for measuring of the ambient audio combined with the audio reproduced by speaker SPKR close to a listener's ear when such headphone 18A, 18B is engaged with the listener's ear. In some embodiments, CODEC IC 20 may receive the signals from reference microphone R, near-speech microphone NS, and error microphone E of each headphone and perform adaptive noise cancellation for each headphone as described herein. In other embodiments, a CODEC IC or another circuit may be present within headphone assembly 13, communicatively coupled to reference microphone R, near-speech microphone NS, and error microphone E, and configured to perform adaptive noise cancellation as described herein.
Referring now to
Referring now to
To implement the above, adaptive filter 34A may have coefficients controlled by SE coefficient control block 33, which may compare the source audio signal and a playback corrected error. The playback corrected error may be equal to error microphone signal err after removal of the equalized source audio signal (as filtered by filter 34A to represent the expected playback audio delivered to error microphone E) by a combiner 36. SE coefficient control block 33 may correlate the actual equalized source audio signal with the components of the equalized source audio signal that are present in error microphone signal err. Adaptive filter 34A may thereby be adapted to generate a secondary estimate signal from the equalized source audio signal, that when subtracted from error microphone signal err to generate the playback corrected error, includes the content of error microphone signal err that is not due to the equalized source audio signal.
Also as shown in
If the degree of convergence of the adaptive response is below a particular threshold (e.g., the adaptive response is adapting over a period of time in excess of a threshold level of adaptation), controller 42 may enable adaptation of the adaptive response. On the other hand, if the degree of convergence of the adaptive response is above a particular threshold (e.g., the adaptive response is adapting over a period of time less than a threshold level of adaptation), controller 42 may disable adaptation of the adaptive response. Example approaches for determining a degree of convergence and the particular thresholds relevant to such approaches may be described in greater detail below in reference to
In some embodiments, controller 42 may disable adaptation of an adaptive response by disabling a coefficient control block (e.g., W coefficient control block 31 and/or SE coefficient control block 33) associated with the adaptive response. In these and other embodiments, controller 42 may disable adaptation of an adaptive response (e.g., response W(z)) by disabling filter 34B and/or filter 34C (filter 34C is described in greater detail below). In these and other embodiments, controller 42 may disable adaptation of an adaptive response (e.g., W(z)) by disabling oversight detectors of ANC circuit 30 used to ensure stability in the adaptation of response W(z).
In some embodiments, controller 42 may, as described in greater detail below with respect to
In some of such embodiments, controller 42 may determine a degree of convergence of adaptive responsive W(z) by monitoring adaptive response W(z), as shown in
At step 402, controller 42 may enable response W(z) to adapt for a first period of time (e.g., 1000 milliseconds). At step 404, at the end of the first period of time, controller 42 may record information indicative of response W(z), such as the response itself or the coefficients of W coefficient control block 31.
At step 406, controller 42 may continue to enable response W(z) to adapt for a second period of time (e.g., 100 milliseconds). At step 408, the end of the second period of time, controller 42 may record information indicative of response W(z), such as the response itself or the coefficients of W coefficient control block 31.
At step 410, controller 42 may compare information indicative of response W(z) at the end of the second period of time to the information indicative of response W(z) recorded at the end of the first period of time to determine the degree of convergence of response W(z). If information indicative of response W(z) at the end of the second period of time is within a predetermined threshold error of the information indicative of response W(z) recorded at the end of the first period of time, controller 42 may determine that response W(z) is substantially converged, and may proceed to step 412. Otherwise, controller 42 may determine that response W(z) is not substantially converged, and may proceed again to step 406.
At step 412, in response to the determination that response W(z) is substantially converged, controller 42 may disable adaptation of response W(z) and power down one or more components associated with adaptation of response W(z) for a period of time (e.g., 1000 milliseconds). At step 414, after adaptation of response W(z) has been disabled for the period of time, controller 42 may enable response W(z) to adapt for an additional period of time (e.g., 100 milliseconds). At step 416, at the end of the additional period of time, controller 42 may record information indicative of response W(z), such as the response itself or the coefficients of W coefficient control block 31.
At step 418, controller 42 may compare information indicative of response W(z) at the end of the additional period of time to the information indicative of response W(z) recorded at the end of the period of time in which adaptation of response W(z) was most-recently enabled to determine the degree of convergence of response W(z). If information indicative of response W(z) at the end of the additional period of time is within a predetermined threshold error of the information indicative of response W(z) recorded at the end of the period of time in which adaptation of response W(z) was most-recently enabled, controller 42 may determine that response W(z) is substantially converged, and may proceed to step 412. Otherwise, controller 42 may determine that response W(z) is not substantially converged, and may proceed again to step 402.
Although
Method 400 may be implemented using wireless telephone 10 or any other system operable to implement method 400. In certain embodiments, method 400 may be implemented partially or fully in software and/or firmware embodied in computer-readable media and executable by a controller.
In addition or alternatively, controller 42 may determine a degree of convergence of adaptive responsive SE(z) by monitoring adaptive response SE(z), as shown in
At step 502, controller 42 may enable response SE(z) to adapt for a first period of time (e.g., 100 milliseconds). At step 504, at the end of the first period of time, controller 42 may record information indicative of response SE(z), such as the response itself or the coefficients of SE coefficient control block 33.
At step 506, controller 42 may continue to enable response SE(z) to adapt for a second period of time (e.g., 10 milliseconds). At step 508, the end of the second period of time, controller 42 may record information indicative of response SE(z), such as the response itself or the coefficients of SE coefficient control block 33.
At step 510, controller 42 may compare information indicative of response SE(z) at the end of the second period of time to the information indicative of response SE(z) recorded at the end of the first period of time to determine the degree of convergence of response SE(z). If information indicative of response SE(z) at the end of the second period of time is within a predetermined threshold error of the information indicative of response SE(z) recorded at the end of the first period of time, controller 42 may determine that response SE(z) is substantially converged, and may proceed to step 512. Otherwise, controller 42 may determine that response SE(z) is not substantially converged, and may proceed again to step 506.
At step 512, in response to the determination that response SE(z) is substantially converged, controller 42 may disable adaptation of response SE(z) and power down one or more components associated with adaptation of response SE(z) for a period of time (e.g., 100 milliseconds). At step 514, after adaptation of response SE(z) has been disabled for the period of time, controller 42 may enable response SE(z) to adapt for an additional period of time (e.g., 10 milliseconds). At step 516, at the end of the additional period of time, controller 42 may record information indicative of response SE(z), such as the response itself or the coefficients of SE coefficient control block 33.
At step 518, controller 42 may compare information indicative of response SE(z) at the end of the additional period of time to the information indicative of response SE(z) recorded at the end of the period of time in which adaptation of response SE(z) was most-recently enabled to determine the degree of convergence of response SE(z). If information indicative of response SE(z) at the end of the additional period of time is within a predetermined threshold error of the information indicative of response SE(z) recorded at the end of the period of time in which adaptation of response SE(z) was most-recently enabled, controller 42 may determine that response SE(z) is substantially converged, and may proceed to step 512. Otherwise, controller 42 may determine that response SE(z) is not substantially converged, and may proceed again to step 502.
Although
Method 500 may be implemented using wireless telephone 10 or any other system operable to implement method 500. In certain embodiments, method 500 may be implemented partially or fully in software and/or firmware embodied in computer-readable media and executable by a controller.
In addition or alternatively, controller 42 may determine a degree of convergence of adaptive responsive W(z) by monitoring both adaptive responses W(z) and SE(z), as shown in
At step 602, controller 42 may enable responses W(z) and SE(z) to adapt for a first period of time. At step 604, at the end of the first period of time, controller 42 may record information indicative of response W(z), such as the response itself or the coefficients of W coefficient control block 31.
At step 606, controller 42 may continue to enable responses W(z) and SE(z) to adapt for a second period of time. At step 608, the end of the second period of time, controller 42 may record information indicative of response W(z), such as the response itself or the coefficients of W coefficient control block 31.
At step 610, controller 42 may compare information indicative of response W(z) at the end of the second period of time to the information indicative of response W(z) recorded at the end of the first period of time to determine the degree of convergence of response W(z). If information indicative of response W(z) at the end of the second period of time is within a predetermined threshold error of the information indicative of response W(z) recorded at the end of the first period of time, controller 42 may determine that response W(z) is substantially converged, and may proceed to step 612. Otherwise, controller 42 may determine that response W(z) is not substantially converged, and may proceed again to step 606.
At step 612, in response to the determination that response W(z) is substantially converged, controller 42 may disable adaptation of response W(z) and power down one or more components associated with adaptation of response W(z), but may enable response SE(z) to continue to adapt. At step 614, controller 42 may record information indicative of response SE(z), such as the response itself or the coefficients of SE coefficient control block 33.
At step 616, after an additional period of time, controller 42 may again record information indicative of response SE(z), such as the response itself or the coefficients of SE coefficient control block 33. At step 618, controller 42 may compare information indicative of response SE(z) at the end of the additional period of time to the information indicative of response SE(z) recorded prior to the additional period of time. If information indicative of response SE(z) at the end of the additional period of time is within a predetermined threshold error of the information indicative of response SE(z) recorded prior to the additional period of time, controller 42 may determine that response SE(z) is substantially converged, and may proceed again to step 616. Otherwise, controller 42 may determine that response SE(z) is not substantially converged, and may proceed again to step 602.
Although
Method 600 may be implemented using wireless telephone 10 or any other system operable to implement method 600. In certain embodiments, method 600 may be implemented partially or fully in software and/or firmware embodied in computer-readable media and executable by a controller.
In these and other embodiments, controller 42 may, as described in greater detail below with respect to
At step 702, controller 42 may enable response W(z) to adapt for a first period of time. At step 704, at the end of the first period of time, controller 42 may record information indicative of the adaptive noise cancellation gain (e.g., the response of the adaptive noise cancellation gain as a function of frequency).
At step 706, controller 42 may continue to enable response W(z) to adapt for a second period of time. At step 708, the end of the second period of time, controller 42 may record information indicative of the adaptive noise cancellation gain (e.g., the response of the adaptive noise cancellation gain as a function of frequency).
At step 710, controller 42 may compare information indicative of the adaptive noise cancellation gain at the end of the second period of time to the information indicative of the adaptive noise cancellation gain recorded at the end of the first period of time to determine the degree of convergence of ANC circuit 30. If information indicative of the adaptive noise cancellation gain at the end of the second period of time is within a predetermined threshold error of the information indicative of the adaptive noise cancellation gain recorded at the end of the first period of time, controller 42 may determine that ANC circuit 30 is substantially converged, and may proceed to step 712. Otherwise, controller 42 may determine that ANC circuit 30 is not substantially converged, and may proceed again to step 706.
At step 712, in response to the determination that ANC circuit 30 is substantially converged, controller 42 may disable adaptation of response W(z) and power down one or more components associated with adaptation of response W(z) for an additional period of time. At step 716, at the end of the additional period of time, controller 42 may record information indicative of the adaptive noise cancellation gain (e.g., the response of the adaptive noise cancellation gain as a function of frequency).
At step 718, controller 42 may compare information indicative of the adaptive noise cancellation gain at the end of the additional period of time to the information indicative of the adaptive noise cancellation gain recorded at the end of the period of time in which adaptation of response W(z) was most-recently enabled to determine the degree of convergence of ANC circuit 30. If information indicative of the adaptive noise cancellation gain at the end of the additional period of time is within a predetermined threshold error of the information indicative of the adaptive noise cancellation gain recorded at the end of the period of time in which adaptation of response W(z) was most-recently enabled, controller 42 may determine that ANC circuit 30 is substantially converged, and may proceed to step 712. Otherwise, controller 42 may determine that ANC circuit 30 is not substantially converged, and may proceed again to step 702. Although
Method 700 may be implemented using wireless telephone 10 or any other system operable to implement method 700. In certain embodiments, method 700 may be implemented partially or fully in software and/or firmware embodied in computer-readable media and executable by a controller.
In addition or alternatively to monitoring the adaptive noise cancellation gain, controller 42 may be configured to determine the degree of convergence of the adaptive response by determining a cross-correlation between the reference microphone signal and the playback corrected error. For example, controller 42 may determine the degree of convergence to be above the particular threshold if the cross-correlation is lesser than a threshold cross-correlation, and responsive to such determination, disable adaptation of the adaptive response (e.g., W(z) and/or SE(z)). Similarly, controller 42 may determine the degree of convergence to be below the particular threshold if the cross-correlation is greater than a threshold cross-correlation, and responsive to such determination, enable adaptation of the adaptive response.
In these and other embodiments, controller 42 may, as described in greater detail below with respect to
At step 802, controller 42 may enable responses W(z) and SE(z) to adapt for a first period of time. At step 804, at the end of the first period of time, controller 42 may record information indicative of the secondary path estimate filter cancellation gain (e.g., the response of the secondary path estimate filter cancellation gain as a function of frequency).
At step 806, controller 42 may continue to enable responses W(z) and SE(z) to adapt for a second period of time. At step 808, at the end of the second period of time, controller 42 may record information indicative of the secondary path estimate filter cancellation gain (e.g., the response of the secondary path estimate filter cancellation gain as a function of frequency).
At step 810, controller 42 may compare information indicative of the secondary path estimate filter cancellation gain at the end of the second period of time to the information indicative of the secondary path estimate filter cancellation gain recorded at the end of the first period of time to determine the degree of convergence of ANC circuit 30. If information indicative of the secondary path estimate filter cancellation gain at the end of the second period of time is within a predetermined threshold error of the information indicative of the secondary path estimate filter cancellation gain recorded at the end of the first period of time, controller 42 may determine that ANC circuit 30 is substantially converged, and may proceed to step 812. Otherwise, controller 42 may determine that ANC circuit 30 is not substantially converged, and may proceed again to step 806.
At step 812, in response to the determination that ANC circuit 30 is substantially converged, controller 42 may disable adaptation of response W(z) and power down one or more components associated with adaptation of response W(z) for an additional period of time. At step 816, at the end of the additional period of time, controller 42 may record information indicative of the secondary path estimate filter cancellation gain (e.g., the response of the secondary path estimate filter cancellation gain as a function of frequency).
At step 818, controller 42 may compare information indicative of the secondary path estimate filter cancellation gain at the end of the additional period of time to the information indicative of the secondary path estimate filter cancellation gain recorded at the end of the period of time in which adaptation of responses W(z) and SE(z) was most-recently enabled to determine the degree of convergence of ANC circuit 30. If information indicative of the secondary path estimate filter cancellation gain at the end of the additional period of time is within a predetermined threshold error of the information indicative of the secondary path estimate filter cancellation gain recorded at the end of the period of time in which adaptation of responses W(z) and SE(z) was most-recently enabled, controller 42 may determine that ANC circuit 30 is substantially converged, and may proceed to step 812. Otherwise, controller 42 may determine that ANC circuit 30 is not substantially converged, and may proceed again to step 802.
Although
Method 800 may be implemented using wireless telephone 10 or any other system operable to implement method 800. In certain embodiments, method 800 may be implemented partially or fully in software and/or firmware embodied in computer-readable media and executable by a controller.
In addition or alternatively to monitoring the secondary path estimate filter cancellation gain, controller 42 may be configured to determine the degree of convergence of the adaptive response by determining a cross-correlation between the source audio signal ds/ia and the playback corrected error. For example, controller 42 may determine the degree of convergence to be above the particular threshold if the cross-correlation is lesser than a threshold cross-correlation, and responsive to such determination, disable adaptation of the adaptive response (e.g., W(z) and/or SE(z)). Similarly, controller 42 may determine the degree of convergence to be below the particular threshold if the cross-correlation is greater than a threshold cross-correlation, and responsive to such determination, enable adaptation of the adaptive response.
Although
As shown in
To implement the above, adaptive filter 34D may have coefficients controlled by SE coefficient control block 33B, which may compare downlink audio signal ds and/or internal audio signal ia and error microphone signal err after removal of the above-described filtered downlink audio signal ds and/or internal audio signal ia, that has been filtered by adaptive filter 34D to represent the expected downlink audio delivered to error microphone E, and which is removed from the output of adaptive filter 34D by a combiner 37 to generate the playback corrected error. SE coefficient control block 33B correlates the actual downlink speech signal ds and/or internal audio signal ia with the components of downlink audio signal ds and/or internal audio signal ia that are present in error microphone signal err. Adaptive filter 34D may thereby be adapted to generate a signal from downlink audio signal ds and/or internal audio signal ia, that when subtracted from error microphone signal err, contains the content of error microphone signal err that is not due to downlink audio signal ds and/or internal audio signal ia.
Also as shown in
In some embodiments, controller 43 may, in a manner similar or analogous to that described in greater detail above with respect to
This disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the example embodiments herein that a person having ordinary skill in the art would comprehend. Similarly, where appropriate, the appended claims encompass all changes, substitutions, variations, alterations, and modifications to the example embodiments herein that a person having ordinary skill in the art would comprehend. Moreover, reference in the appended claims to an apparatus or system or a component of an apparatus or system being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses that apparatus, system, or component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or component is so adapted, arranged, capable, configured, enabled, operable, or operative.
All examples and conditional language recited herein are intended for pedagogical objects to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are construed as being without limitation to such specifically recited examples and conditions. Although embodiments of the present inventions have been described in detail, it should be understood that various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the disclosure.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5010401 | Murakami | Apr 1991 | A |
| 5117401 | Feintuch | May 1992 | A |
| 5251263 | Andrea et al. | Oct 1993 | A |
| 5278913 | Delfosse et al. | Jan 1994 | A |
| 5321759 | Yuan | Jun 1994 | A |
| 5337365 | Hamabe et al. | Aug 1994 | A |
| 5359662 | Yuan et al. | Oct 1994 | A |
| 5377276 | Terai et al. | Dec 1994 | A |
| 5410605 | Sawada et al. | Apr 1995 | A |
| 5425105 | Lo et al. | Jun 1995 | A |
| 5445517 | Kondou et al. | Aug 1995 | A |
| 5465413 | Enge et al. | Nov 1995 | A |
| 5481615 | Eatwell et al. | Jan 1996 | A |
| 5548681 | Gleaves et al. | Aug 1996 | A |
| 5559893 | Krokstad | Sep 1996 | A |
| RE35414 | Murakami | Dec 1996 | E |
| 5586190 | Trantow et al. | Dec 1996 | A |
| 5640450 | Watanabe | Jun 1997 | A |
| 5668747 | Ohashi | Sep 1997 | A |
| 5696831 | Inanga | Dec 1997 | A |
| 5699437 | Finn | Dec 1997 | A |
| 5706344 | Finn | Jan 1998 | A |
| 5740256 | Castello Da Costa et al. | Apr 1998 | A |
| 5768124 | Stothers et al. | Jun 1998 | A |
| 5809152 | Nakamura et al. | Sep 1998 | A |
| 5815582 | Claybaugh et al. | Sep 1998 | A |
| 5832095 | Daniels | Nov 1998 | A |
| 5909498 | Smith | Jun 1999 | A |
| 5940519 | Kuo | Aug 1999 | A |
| 5946391 | Dragwidge et al. | Aug 1999 | A |
| 5970092 | Currivan | Oct 1999 | A |
| 5978473 | Rasmusson | Nov 1999 | A |
| 5991418 | Kuo | Nov 1999 | A |
| 6041126 | Terai et al. | Mar 2000 | A |
| 6118878 | Jones | Sep 2000 | A |
| 6185300 | Romesburg | Feb 2001 | B1 |
| 6219427 | Kates et al. | Apr 2001 | B1 |
| 6278786 | McIntosh | Aug 2001 | B1 |
| 6282176 | Hemkumar | Aug 2001 | B1 |
| 6317501 | Matsuo | Nov 2001 | B1 |
| 6381272 | Ali | Apr 2002 | B1 |
| 6415247 | Kimura | Jul 2002 | B1 |
| 6418228 | Terai et al. | Jul 2002 | B1 |
| 6434110 | Hemkumar | Aug 2002 | B1 |
| 6434246 | Kates et al. | Aug 2002 | B1 |
| 6434247 | Kates et al. | Aug 2002 | B1 |
| 6522746 | Marchok et al. | Feb 2003 | B1 |
| 6683960 | Fujii et al. | Jan 2004 | B1 |
| 6728380 | Zhu | Apr 2004 | B1 |
| 6766292 | Chandran et al. | Jul 2004 | B1 |
| 6768795 | Feltstrom et al. | Jul 2004 | B2 |
| 6850617 | Weigand | Feb 2005 | B1 |
| 6940982 | Watkins | Sep 2005 | B1 |
| 7058463 | Ruha et al. | Jun 2006 | B1 |
| 7103188 | Jones | Sep 2006 | B1 |
| 7110864 | Restrepo et al. | Sep 2006 | B2 |
| 7181030 | Rasmussen et al. | Feb 2007 | B2 |
| 7330739 | Somayajula | Feb 2008 | B2 |
| 7365669 | Melanson | Apr 2008 | B1 |
| 7368918 | Henson et al. | May 2008 | B2 |
| 7441173 | Restrepo et al. | Oct 2008 | B2 |
| 7466838 | Moseley | Dec 2008 | B1 |
| 7680456 | Muhammad et al. | Mar 2010 | B2 |
| 7742790 | Konchitsky et al. | Jun 2010 | B2 |
| 7817808 | Konchitsky et al. | Oct 2010 | B2 |
| 7885417 | Christoph | Feb 2011 | B2 |
| 8019050 | Mactavish et al. | Sep 2011 | B2 |
| 8107637 | Asada et al. | Jan 2012 | B2 |
| 8165313 | Carreras | Apr 2012 | B2 |
| 8249262 | Chua et al. | Aug 2012 | B2 |
| 8290537 | Lee et al. | Oct 2012 | B2 |
| 8325934 | Kuo | Dec 2012 | B2 |
| 8363856 | Lesso | Jan 2013 | B2 |
| 8374358 | Buck et al. | Feb 2013 | B2 |
| 8379884 | Horibe et al. | Feb 2013 | B2 |
| 8401200 | Tiscareno et al. | Mar 2013 | B2 |
| 8442251 | Jensen et al. | May 2013 | B2 |
| 8526627 | Asao et al. | Sep 2013 | B2 |
| 8804974 | Melanson | Aug 2014 | B1 |
| 8848936 | Kwatra et al. | Sep 2014 | B2 |
| 8907829 | Naderi | Dec 2014 | B1 |
| 8908877 | Abdollahzadeh Milani et al. | Dec 2014 | B2 |
| 8942976 | Li | Jan 2015 | B2 |
| 8948407 | Alderson et al. | Feb 2015 | B2 |
| 8958571 | Kwatra et al. | Feb 2015 | B2 |
| 8977545 | Zeng et al. | Mar 2015 | B2 |
| 9066176 | Hendrix et al. | Jun 2015 | B2 |
| 9082391 | Yermeche | Jul 2015 | B2 |
| 9094744 | Lu et al. | Jul 2015 | B1 |
| 9106989 | Li et al. | Aug 2015 | B2 |
| 9107010 | Abdollahzadeh Milani et al. | Aug 2015 | B2 |
| 9264808 | Zhou et al. | Feb 2016 | B2 |
| 9294836 | Zhou et al. | Mar 2016 | B2 |
| 9301048 | Sugiyama | Mar 2016 | B2 |
| 20010053228 | Jones | Dec 2001 | A1 |
| 20020003887 | Zhang et al. | Jan 2002 | A1 |
| 20030063759 | Brennan et al. | Apr 2003 | A1 |
| 20030072439 | Gupta | Apr 2003 | A1 |
| 20030185403 | Sibbald | Oct 2003 | A1 |
| 20040047464 | Yu et al. | Mar 2004 | A1 |
| 20040120535 | Woods | Jun 2004 | A1 |
| 20040165736 | Hetherington et al. | Aug 2004 | A1 |
| 20040167777 | Hetherington et al. | Aug 2004 | A1 |
| 20040176955 | Farinelli, Jr. | Sep 2004 | A1 |
| 20040196992 | Ryan | Oct 2004 | A1 |
| 20040202333 | Czermak et al. | Oct 2004 | A1 |
| 20040240677 | Onishi et al. | Dec 2004 | A1 |
| 20040242160 | Ichikawa et al. | Dec 2004 | A1 |
| 20040264706 | Ray et al. | Dec 2004 | A1 |
| 20050004796 | Trump et al. | Jan 2005 | A1 |
| 20050018862 | Fisher | Jan 2005 | A1 |
| 20050117754 | Sakawaki | Jun 2005 | A1 |
| 20050207585 | Christoph | Sep 2005 | A1 |
| 20050240401 | Ebenezer | Oct 2005 | A1 |
| 20060035593 | Leeds | Feb 2006 | A1 |
| 20060055910 | Lee | Mar 2006 | A1 |
| 20060069556 | Nadjar et al. | Mar 2006 | A1 |
| 20060109941 | Keele, Jr. | May 2006 | A1 |
| 20060153400 | Fujita et al. | Jul 2006 | A1 |
| 20070030989 | Kates | Feb 2007 | A1 |
| 20070033029 | Sakawaki | Feb 2007 | A1 |
| 20070038441 | Inoue et al. | Feb 2007 | A1 |
| 20070047742 | Taenzer et al. | Mar 2007 | A1 |
| 20070053524 | Haulick et al. | Mar 2007 | A1 |
| 20070076896 | Hosaka et al. | Apr 2007 | A1 |
| 20070154031 | Avendano et al. | Jul 2007 | A1 |
| 20070208520 | Zhang et al. | Sep 2007 | A1 |
| 20070258597 | Rasmussen et al. | Nov 2007 | A1 |
| 20070297620 | Choy | Dec 2007 | A1 |
| 20080019548 | Avendano | Jan 2008 | A1 |
| 20080101589 | Horowitz et al. | May 2008 | A1 |
| 20080101622 | Sugiyama | May 2008 | A1 |
| 20080107281 | Togami et al. | May 2008 | A1 |
| 20080144853 | Sommerfeldt et al. | Jun 2008 | A1 |
| 20080166002 | Amsel | Jul 2008 | A1 |
| 20080177532 | Greiss et al. | Jul 2008 | A1 |
| 20080181422 | Christoph | Jul 2008 | A1 |
| 20080226098 | Haulick et al. | Sep 2008 | A1 |
| 20080240413 | Mohammed et al. | Oct 2008 | A1 |
| 20080240455 | Inoue et al. | Oct 2008 | A1 |
| 20080240457 | Innoue et al. | Oct 2008 | A1 |
| 20090012783 | Klein | Jan 2009 | A1 |
| 20090034748 | Sibbald | Feb 2009 | A1 |
| 20090041260 | Jorgensen et al. | Feb 2009 | A1 |
| 20090046867 | Clemow | Feb 2009 | A1 |
| 20090060222 | Jeong et al. | Mar 2009 | A1 |
| 20090080670 | Solbeck | Mar 2009 | A1 |
| 20090086990 | Christoph | Apr 2009 | A1 |
| 20090136057 | Taenzer | May 2009 | A1 |
| 20090175466 | Elko et al. | Jul 2009 | A1 |
| 20090196429 | Ramakrishnan et al. | Aug 2009 | A1 |
| 20090202024 | Inoue | Aug 2009 | A1 |
| 20090220107 | Every et al. | Sep 2009 | A1 |
| 20090238369 | Ramakrishnan et al. | Sep 2009 | A1 |
| 20090245529 | Asada et al. | Oct 2009 | A1 |
| 20090254340 | Sun et al. | Oct 2009 | A1 |
| 20090290718 | Kahn et al. | Nov 2009 | A1 |
| 20090296965 | Kojima | Dec 2009 | A1 |
| 20090304200 | Kim et al. | Dec 2009 | A1 |
| 20090311979 | Husted et al. | Dec 2009 | A1 |
| 20100014683 | Maeda et al. | Jan 2010 | A1 |
| 20100014685 | Wurm | Jan 2010 | A1 |
| 20100061564 | Clemow et al. | Mar 2010 | A1 |
| 20100069114 | Lee et al. | Mar 2010 | A1 |
| 20100082339 | Konchitsky et al. | Apr 2010 | A1 |
| 20100098263 | Pan et al. | Apr 2010 | A1 |
| 20100098265 | Pan et al. | Apr 2010 | A1 |
| 20100124335 | Shridhar et al. | May 2010 | A1 |
| 20100124336 | Shridhar et al. | May 2010 | A1 |
| 20100124337 | Wertz et al. | May 2010 | A1 |
| 20100131269 | Park et al. | May 2010 | A1 |
| 20100142715 | Goldstein et al. | Jun 2010 | A1 |
| 20100150367 | Mizuno | Jun 2010 | A1 |
| 20100158330 | Guissin et al. | Jun 2010 | A1 |
| 20100166203 | Peissig et al. | Jul 2010 | A1 |
| 20100166206 | Macours | Jul 2010 | A1 |
| 20100183175 | Chen et al. | Jul 2010 | A1 |
| 20100195838 | Bright | Aug 2010 | A1 |
| 20100195844 | Christoph et al. | Aug 2010 | A1 |
| 20100207317 | Iwami et al. | Aug 2010 | A1 |
| 20100226210 | Kordis et al. | Sep 2010 | A1 |
| 20100246855 | Chen | Sep 2010 | A1 |
| 20100266137 | Sibbald et al. | Oct 2010 | A1 |
| 20100272276 | Carreras et al. | Oct 2010 | A1 |
| 20100272283 | Carreras et al. | Oct 2010 | A1 |
| 20100272284 | Marcel et al. | Oct 2010 | A1 |
| 20100274564 | Bakalos et al. | Oct 2010 | A1 |
| 20100284546 | DeBrunner et al. | Nov 2010 | A1 |
| 20100291891 | Ridgers et al. | Nov 2010 | A1 |
| 20100296666 | Lin | Nov 2010 | A1 |
| 20100296668 | Lee et al. | Nov 2010 | A1 |
| 20100310086 | Magrath et al. | Dec 2010 | A1 |
| 20100310087 | Ishida | Dec 2010 | A1 |
| 20100316225 | Saito et al. | Dec 2010 | A1 |
| 20100322430 | Isberg | Dec 2010 | A1 |
| 20110002468 | Tanghe | Jan 2011 | A1 |
| 20110007907 | Park et al. | Jan 2011 | A1 |
| 20110026724 | Doclo | Feb 2011 | A1 |
| 20110091047 | Konchitsky et al. | Apr 2011 | A1 |
| 20110096933 | Eastty | Apr 2011 | A1 |
| 20110106533 | Yu | May 2011 | A1 |
| 20110116643 | Tiscareno | May 2011 | A1 |
| 20110129098 | Delano et al. | Jun 2011 | A1 |
| 20110130176 | Magrath et al. | Jun 2011 | A1 |
| 20110142247 | Fellers et al. | Jun 2011 | A1 |
| 20110144984 | Konchitsky | Jun 2011 | A1 |
| 20110150257 | Jensen | Jun 2011 | A1 |
| 20110158419 | Theverapperuma et al. | Jun 2011 | A1 |
| 20110206214 | Christoph et al. | Aug 2011 | A1 |
| 20110222698 | Asao et al. | Sep 2011 | A1 |
| 20110222701 | Donaldson et al. | Sep 2011 | A1 |
| 20110249826 | Van Leest | Oct 2011 | A1 |
| 20110288860 | Schevciw et al. | Nov 2011 | A1 |
| 20110293103 | Park | Dec 2011 | A1 |
| 20110299695 | Nicholson | Dec 2011 | A1 |
| 20110305347 | Wurm | Dec 2011 | A1 |
| 20110317848 | Ivanov et al. | Dec 2011 | A1 |
| 20120057720 | Van Leest | Mar 2012 | A1 |
| 20120084080 | Konchitsky | Apr 2012 | A1 |
| 20120135787 | Kusunoki et al. | May 2012 | A1 |
| 20120140917 | Nicholson et al. | Jun 2012 | A1 |
| 20120140942 | Loeda | Jun 2012 | A1 |
| 20120140943 | Hendrix | Jun 2012 | A1 |
| 20120148062 | Scarlett et al. | Jun 2012 | A1 |
| 20120155666 | Nair | Jun 2012 | A1 |
| 20120163580 | Fujita | Jun 2012 | A1 |
| 20120170766 | Alves et al. | Jul 2012 | A1 |
| 20120185524 | Clark | Jul 2012 | A1 |
| 20120207317 | Abdollahzadeh Milani et al. | Aug 2012 | A1 |
| 20120215519 | Park et al. | Aug 2012 | A1 |
| 20120250873 | Bakalos et al. | Oct 2012 | A1 |
| 20120259626 | Li et al. | Oct 2012 | A1 |
| 20120263317 | Shin et al. | Oct 2012 | A1 |
| 20120281850 | Hyatt | Nov 2012 | A1 |
| 20120300958 | Klemmensen | Nov 2012 | A1 |
| 20120300960 | Mackay et al. | Nov 2012 | A1 |
| 20120308021 | Kwatra et al. | Dec 2012 | A1 |
| 20120308024 | Alderson | Dec 2012 | A1 |
| 20120308025 | Hendrix et al. | Dec 2012 | A1 |
| 20120308026 | Karnath et al. | Dec 2012 | A1 |
| 20120308027 | Kwatra | Dec 2012 | A1 |
| 20120308028 | Kwatra et al. | Dec 2012 | A1 |
| 20120310640 | Kwatra et al. | Dec 2012 | A1 |
| 20120316872 | Stoltz et al. | Dec 2012 | A1 |
| 20130010982 | Elko et al. | Jan 2013 | A1 |
| 20130034236 | Hung | Feb 2013 | A1 |
| 20130083939 | Fellers | Apr 2013 | A1 |
| 20130156238 | Birch et al. | Jun 2013 | A1 |
| 20130197905 | Sugiyama | Aug 2013 | A1 |
| 20130222516 | Do et al. | Aug 2013 | A1 |
| 20130243198 | Van Rumpt | Sep 2013 | A1 |
| 20130243225 | Yokota | Sep 2013 | A1 |
| 20130259251 | Bakalos | Oct 2013 | A1 |
| 20130272539 | Kim et al. | Oct 2013 | A1 |
| 20130287218 | Alderson et al. | Oct 2013 | A1 |
| 20130287219 | Hendrix et al. | Oct 2013 | A1 |
| 20130301842 | Hendrix et al. | Nov 2013 | A1 |
| 20130301846 | Alderson | Nov 2013 | A1 |
| 20130301847 | Alderson et al. | Nov 2013 | A1 |
| 20130301848 | Zhou | Nov 2013 | A1 |
| 20130301849 | Alderson | Nov 2013 | A1 |
| 20130315403 | Samuelsson | Nov 2013 | A1 |
| 20130343556 | Bright | Dec 2013 | A1 |
| 20130343571 | Rayala et al. | Dec 2013 | A1 |
| 20140036127 | Pong et al. | Feb 2014 | A1 |
| 20140044275 | Goldstein et al. | Feb 2014 | A1 |
| 20140050332 | Nielsen et al. | Feb 2014 | A1 |
| 20140051483 | Schoerkmaier | Feb 2014 | A1 |
| 20140072134 | Po et al. | Mar 2014 | A1 |
| 20140072135 | Bajic et al. | Mar 2014 | A1 |
| 20140086425 | Jensen et al. | Mar 2014 | A1 |
| 20140126735 | Gauger, Jr. | May 2014 | A1 |
| 20140169579 | Azmi | Jun 2014 | A1 |
| 20140177851 | Kitazawa et al. | Jun 2014 | A1 |
| 20140177890 | Hojlund et al. | Jun 2014 | A1 |
| 20140211953 | Alderson et al. | Jul 2014 | A1 |
| 20140226827 | Abdollahzadeh Milani et al. | Aug 2014 | A1 |
| 20140270223 | Li et al. | Sep 2014 | A1 |
| 20140270224 | Zhou et al. | Sep 2014 | A1 |
| 20140277022 | Hendrix et al. | Sep 2014 | A1 |
| 20140294182 | Axelsson | Oct 2014 | A1 |
| 20140307887 | Alderson et al. | Oct 2014 | A1 |
| 20140307888 | Alderson et al. | Oct 2014 | A1 |
| 20140307890 | Zhou et al. | Oct 2014 | A1 |
| 20140307899 | Hendrix et al. | Oct 2014 | A1 |
| 20140314244 | Yong et al. | Oct 2014 | A1 |
| 20140314246 | Hellmann | Oct 2014 | A1 |
| 20140314247 | Zhang | Oct 2014 | A1 |
| 20140341388 | Goldstein | Nov 2014 | A1 |
| 20140369517 | Zhou et al. | Dec 2014 | A1 |
| 20150078572 | Abdollahzadeh Milani et al. | Mar 2015 | A1 |
| 20150092953 | Abdollahzadeh Milani et al. | Apr 2015 | A1 |
| 20150104032 | Kwatra et al. | Apr 2015 | A1 |
| 20150161980 | Alderson et al. | Jun 2015 | A1 |
| 20150161981 | Kwatra | Jun 2015 | A1 |
| 20150163592 | Alderson | Jun 2015 | A1 |
| 20150168467 | Haneda | Jun 2015 | A1 |
| 20150172813 | Goto | Jun 2015 | A1 |
| 20150256660 | Kaller et al. | Sep 2015 | A1 |
| 20150256953 | Kwatra et al. | Sep 2015 | A1 |
| 20150269926 | Alderson et al. | Sep 2015 | A1 |
| 20160180830 | Lu et al. | Jun 2016 | A1 |
| Number | Date | Country |
|---|---|---|
| 102011013343 | Sep 2012 | DE |
| 0412902 | Feb 1991 | EP |
| 0756407 | Jan 1997 | EP |
| 0898266 | Feb 1999 | EP |
| 1691577 | Aug 2006 | EP |
| 1880699 | Jan 2008 | EP |
| 1947642 | Jul 2008 | EP |
| 2133866 | Dec 2009 | EP |
| 2237573 | Oct 2010 | EP |
| 2216774 | Aug 2011 | EP |
| 2395500 | Dec 2011 | EP |
| 2395501 | Dec 2011 | EP |
| 2551845 | Jan 2013 | EP |
| 2583074 | Apr 2013 | EP |
| 2984648 | Feb 2016 | EP |
| 2987160 | Feb 2016 | EP |
| 2987162 | Feb 2016 | EP |
| 2987337 | Feb 2016 | EP |
| 2401744 | Nov 2004 | GB |
| 2436657 | Oct 2007 | GB |
| 2455821 | Jun 2009 | GB |
| 2455824 | Jun 2009 | GB |
| 2455828 | Jun 2009 | GB |
| 2484722 | Apr 2012 | GB |
| H06186985 | Jul 1994 | JP |
| H06232755 | Aug 1994 | JP |
| 07325588 | Dec 1995 | JP |
| H11305783 | Nov 1999 | JP |
| 2000089770 | Mar 2000 | JP |
| 2002010355 | Jan 2002 | JP |
| 2004007107 | Jan 2004 | JP |
| 2006217542 | Aug 2006 | JP |
| 2007060644 | Mar 2007 | JP |
| 2008015046 | Jan 2008 | JP |
| 2010277025 | Dec 2010 | JP |
| 2011061449 | Mar 2011 | JP |
| 1999011045 | Mar 1999 | WO |
| 2003015074 | Feb 2003 | WO |
| 2003015275 | Feb 2003 | WO |
| WO2004009007 | Jan 2004 | WO |
| 2004017303 | Feb 2004 | WO |
| 2006125061 | Nov 2006 | WO |
| 2006128768 | Dec 2006 | WO |
| 2007007916 | Jan 2007 | WO |
| 2007011337 | Jan 2007 | WO |
| 2007110807 | Oct 2007 | WO |
| 2007113487 | Nov 2007 | WO |
| 2009041012 | Apr 2009 | WO |
| 2009110087 | Sep 2009 | WO |
| 2010117714 | Oct 2010 | WO |
| 2011035061 | Mar 2011 | WO |
| 2012107561 | Aug 2012 | WO |
| 2012119808 | Sep 2012 | WO |
| 2012134874 | Oct 2012 | WO |
| 2012166273 | Dec 2012 | WO |
| 2012166388 | Dec 2012 | WO |
| 2013106370 | Jul 2013 | WO |
| 2014158475 | Oct 2014 | WO |
| 2014168685 | Oct 2014 | WO |
| 2014172005 | Oct 2014 | WO |
| 2014172006 | Oct 2014 | WO |
| 2014172010 | Oct 2014 | WO |
| 2014172019 | Oct 2014 | WO |
| 2014172021 | Oct 2014 | WO |
| 2014200787 | Dec 2014 | WO |
| 2015038255 | Mar 2015 | WO |
| 2015088639 | Jun 2015 | WO |
| 2015088639 | Jun 2015 | WO |
| 2015088651 | Jun 2015 | WO |
| 2015088653 | Jun 2015 | WO |
| 2015134225 | Sep 2015 | WO |
| 2015191691 | Dec 2015 | WO |
| 2016100602 | Jun 2016 | WO |
| Entry |
|---|
| Ray, Laura et al., Hybrid Feedforward-Feedback Active Noise Reduction for Hearing Protection and Communication, The Journal of the Acoustical Society of America, American Institute of Physics for the Acoustical Society of America, New York, NY, vol. 120, No. 4, Jan. 2006, pp. 2026-2036. |
| International Patent Application No. PCT/US2014/017112, International Search Report and Written Opinion, dated May 8, 2015, 22 pages. |
| International Search Report and Written Opinion of the International Searching Authority, International Patent Application No. PCT/US2014/017343, dated Aug. 8 2014, 22 pages. |
| International Search Report and Written Opinion of the International Searching Authority, International Patent Application No. PCT/US2014/018027, dated Sep. 4, 2014, 14 pages. |
| International Search Report and Written Opinion of the International Searching Authority, International Patent Application No. PCT/US2014/017374, dated Sep. 8, 2014, 13 pages. |
| International Search Report and Written Opinion of the International Searching Authority, International Patent Application No. PCT/US2014/019395, dated Sep. 9, 2014, 14 pages. |
| International Search Report and Written Opinion of the International Searching Authority, International Patent Application No. PCT/US2014/019469, dated Sep. 12, 2014, 13 pages. |
| Feng, Jinwei et al., “A broadband self-tuning active noise equaliser”, Signal Processing, Elsevier Science Publishers B.V. Amsterdam, NL, vol. 62, No. 2, Oct. 1, 1997, pp. 251-256. |
| Zhang, Ming et al., “A Robust Online Secondary Path Modeling Method with Auxiliary Noise Power Scheduling Strategy and Norm Constraint Manipulation”, IEEE Transactions on Speech and Audio Processing, IEEE Service Center, New York, NY, vol. 11, No. 1, Jan. 1, 2003. |
| Lopez-Gaudana, Edgar et al., “A hybrid active noise cancelling with secondary path modeling”, 51st Midwest Symposium on Circuits and Systems, 2008, MWSCAS 2008, Aug. 10, 2008, pp. 277-280. |
| Widrow, B. et al., Adaptive Noise Cancelling: Principles and Applications, Proceedings of the IEEE, IEEE, New York, NY, U.S., vol. 63, No. 13, Dec. 1975, pp. 1692-1716. |
| Morgan, Dennis R. et al., A Delayless Subband Adaptive Filter Architecture, IEEE Transactions on Signal Processing, IEEE Service Center, New York, NY, U.S., vol. 43, No. 8, Aug. 1995, pp. 1819-1829. |
| International Patent Application No. PCT/US2014/040999, International Search Report and Written Opinion, dated Oct. 18, 2014, 12 pages. |
| International Patent Application No. PCT/US2013/049407, International Search Report and Written Opinion, dated Jun. 18, 2014, 13 pages. |
| Kou, Sen and Tsai, Jianming, Residual noise shaping technique for active noise control systems, J. Acoust. Soc. Am. 95 (3), Mar. 1994, pp. 1665-1668. |
| Pfann, et al., “LMS Adaptive Filtering with Delta-Sigma Modulated Input Signals,” IEEE Signal Processing Letters, Apr. 1998, pp. 95-97, vol. 5, No. 4, IEEE Press, Piscataway, NJ. |
| Toochinda, et al., “A Single-Input Two-Output Feedback Formulation for ANC Problems,” Proceedings of the 2001 American Control Conference, Jun. 2001, pp. 923-928, vol. 2, Arlington, VA. |
| Kuo, et al., “Active Noise Control: A Tutorial Review,” Proceedings of the IEEE, Jun. 1999, pp. 943-973, vol. 87, No. 6, IEEE Press, Piscataway, NJ. |
| Johns, et al., “Continuous-Time LMS Adaptive Recursive Filters,” IEEE Transactions on Circuits and Systems, Jul. 1991, pp. 769-778, vol. 38, No. 7, IEEE Press, Piscataway, NJ. |
| Shoval, et al., “Comparison of DC Offset Effects in Four LMS Adaptive Algorithms,” IEEE Transactions on Circuits and Systems II: Analog and Digital Processing, Mar. 1995, pp. 176-185, vol. 42, Issue 3, IEEE Press, Piscataway, NJ. |
| Mali, Dilip, “Comparison of DC Offset Effects on LMB Algorithm and its Derivatives,” International Journal of Recent Trends in Engineering, May 2009, pp. 323-328, vol. 1, No. 1, Academy Publisher. |
| Kates, James M., “Principles of Digital Dynamic Range Compression,” Trends in Amplification, Spring 2005, pp. 45-76, vol. 9, No. 2, Sage Publications. |
| Gao, et al., “Adaptive Linearization of a Loudspeaker,” IEEE International Conference on Acoustics, Speech, and Signal Processing, Apr. 14-17, 1991, pp. 3589-3592, Toronto, Ontario, CA. |
| Silva, et al., “Convex Combination of Adaptive Filters With Different Tracking Capabilities,” IEEE International Conference on Acoustics, Speech, and Signal Processing, Apr. 15-20, 2007, pp. III 925-928, vol. 3, Honolulu, HI, USA. |
| Akhtar, et al., “A Method for Online Secondary Path Modeling in Active Noise Control Systems,” IEEE International Symposium On Circuits and Systems, May 23-26, 2005, pp. 264-267, vol. 1, Kobe, Japan. |
| Davari, et al., “A New Online Secondary Path Modeling Method for Feedforward Active Noise Control Systems,” IEEE International Conference on Industrial Technology, Apr. 21-24, 2008, pp. 1-6, Chengdu, China. |
| Lan, et al., “An Active Noise Control System Using Online Secondary Path Modeling With Reduced Auxiliary Noise,” IEEE Signal Processing Letters, Jan. 2002, pp. 16-18, vol. 9, Issue 1, IEEE Press, Piscataway, NJ. |
| Liu, et al., “Analysis of Online Secondary Path Modeling With Auxiliary Noise Scaled by Residual Noise Signal,” IEEE Transactions on Audio, Speech and Language Processing, Nov. 2010, pp. 1978-1993, vol. 18, Issue 8, IEEE Press, Piscataway, NJ. |
| Booji, P.S., Berkhoff, A.P., Virtual sensors for local, three dimensional, broadband multiple-channel active noise control and the effects on the quiet zones, Proceedings of ISMA2010 including USD2010, pp. 151-166. |
| Lopez-Caudana, Edgar Omar, Active Noise Cancellation: The Unwanted Signal and The Hybrid Solution, Adaptive Filtering Applications, Dr. Lino Garcia, ISBN: 978-953-307-306-4, InTech. |
| D. Senderowicz et al., “Low-Voltage Double-Sampled Delta-Sigma Converters,” IEEE J. Solid-State Circuits, vol. 32 No. 12, pp. 1907-1919, Dec. 1997, 13 pages. |
| Hurst, P.J. and Dyer, K.C., “An improved double sampling scheme for switched-capacitor delta-sigma modulators,” IEEE Int. Symp. Circuits Systems, May 1992, vol. 3, pp. 1179-1182, 4 pages. |
| Milani, et al., “On Maximum Achievable Noise Reduction in ANC Systems”, Proceedings of the IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2010, Mar. 14-19, 2010 pp. 349-352. |
| Ryan, et al., “Optimum near-field performance of microphone arrays subject to a far-field beampattern constraint”, 2248 J. Acoust. Soc. Am. 108, Nov. 2000. |
| Cohen, et al., “Noise Estimation by Minima Controlled Recursive Averaging for Robust Speech Enhancement”, IEEE Signal Processing Letters, vol. 9, No. 1, Jan. 2002. |
| Martin, “Noise Power Spectral Density Estimation Based on Optimal Smoothing and Minimum Statistics”, IEEE Trans. on Speech and Audio Processing, col. 9, No. 5, Jul. 2001. |
| Martin, “Spectral Subtraction Based on Minimum Statistics”, Proc. 7th EUSIPCO '94, Edinburgh, U.K., Sep. 13-16, 1994, pp. 1182-1195. |
| Cohen, “Noise Spectrum Estimation in Adverse Environments: Improved Minima Controlled Recursive Averaging”, IEEE Trans. on Speech & Audio Proc., vol. 11, Issue 5, Sep. 2003. |
| Black, John W., “An Application of Side-Tone in Subjective Tests of Microphones and Headsets”, Project Report No. NM 001 064.01.20, Research Report of the U.S. Naval School of Aviation Medicine, Feb. 1, 1954, 12 pages (pp. 1-12 in pdf), Pensacola, FL, US. |
| Lane, et al., “Voice Level: Autophonic Scale, Perceived Loudness, and the Effects of Sidetone”, The Journal of the Acoustical Society of America, Feb. 1961, pp. 160-167, vol. 33, No. 2., Cambridge, MA, US. |
| Liu, et al., “Compensatory Responses to Loudness-shifted Voice Feedback During Production of Mandarin Speech”, Journal of the Acoustical Society of America, Oct. 2007, pp. 2405-2412, vol. 122, No. 4. |
| Paepcke, et al., “Yelling in the Hall: Using Sidetone to Address a Problem with Mobile Remote Presence Systems”, Symposium on User Interface Software and Technology, Oct. 16-19, 2011, 10 pages (pp. 1-10 in pdf), Santa Barbara, CA, US. |
| Peters, Robert W., “The Effect of High-Pass and Low-Pass Filtering of Side-Tone Upon Speaker Intelligibility”, Project Report No. NM 001 064.01.25, Research Report of the U.S. Naval School of Aviation Medicine, Aug. 16, 1954, 13 pages (pp. 1-13 in pdf), Pensacola, FL, US. |
| Therrien, et al., “Sensory Attenuation of Self-Produced Feedback: The Lombard Effect Revisited”, PLOS ONE, Nov. 2012, pp. 1-7, vol. 7, Issue 11, e49370, Ontario, Canada. |
| Campbell, Mikey, “Apple looking into self-adjusting earbud headphones with noise cancellation tech”, Apple Insider, Jul. 4, 2013, pp. 1-10 (10 pages in pdf), downloaded on May 14, 2014 from http://appleinsider.com/articles/13/07/04/apple-looking-into-self-adjusting-earbud-headphones-with-noise-cancellation-tech. |
| International Patent Application No. PCT/US2014/017096, International Search Report and Written Opinion, dated May 27, 2014, 11 pages. |
| International Patent Application No. PCT/US2014/049600, International Search Report and Written Opinion, dated Jan. 14, 2015, 12 pages. |
| International Patent Application No. PCT/US2014/061753, International Search Report and Written Opinion, dated Feb. 9, 2015, 8 pages. |
| International Patent Application No. PCT/US2014/061548, International Search Report and Written Opinion, dated Feb. 12, 2015, 13 pages. |
| International Patent Application No. PCT/US2014/060277, International Search Report and Written Opinion, dated Mar. 9, 2015, 11 pages. |
| Jin, et al., “A simultaneous equation method-based online secondary path modeling algorithm for active noise control”, Journal of Sound and Vibration, Apr. 25, 2007, pp. 455-474, vol. 303, No. 3-5, London, GB. |
| Erkelens et al., “Tracking of Nonstationary Noise Based on Data-Driven Recursive Noise Power Estimation”, IEEE Transactions on Audio Speech, and Language Processing, vol. 16, No. 6, Aug. 2008. |
| Rao et al., “A Novel Two Stage Single Channle Speech Enhancement Technique”, India Conference (INDICON) 2011 Annual IEEE, IEEE, Dec. 15, 2011. |
| Rangachari et al., “A noise-estimation algorithm for highly non-stationary environments” Speech Communication, Elsevier Science Publishers, vol. 48, No. 2, Feb. 1, 2006. |
| International Patent Application No. PCT/US2015/017124, International Search Report and Written Opinion, dated Jul. 13, 2015, 19 pages. |
| International Patent Application No. PCT/US2015/035073, International Search Report and Written Opinion, dated Oct. 8, 2015, 11 pages. |
| Parkins, et al., Narrowband and broadband active control in an enclosure using the acoustic energy density, J. Acoust. Soc. Am. Jul. 2000, pp. 192-203, vol. 108, issue 1, U.S. |
| International Patent Application No. PCT/US2015/022113, International Search Report and Written Opinion, dated Jul. 23, 2015, 13 pages. |
| Combined Search and Examination Report, Application No. GB1519000.2, dated Apr. 21, 2016, 5 pages. |
| International Patent Application No. PCT/US2015/066260, International Search Report and Written Opinion, dated Apr. 21, 2016, 13 pages. |
| English machine translation of JP 2006-217542 A (Okumura, Hiroshi; Howling Suppression Device and Loudspeaker, published Aug. 2006). |
| Combined Search and Examination Report, Application No. GB1512832.5, dated Jan. 28, 2016, 7 pages. |
| Number | Date | Country | |
|---|---|---|---|
| 20150365761 A1 | Dec 2015 | US |
