ERROR-SIGNAL CONTENT CONTROLLED ADAPTATION OF SECONDARY AND LEAKAGE PATH MODELS IN NOISE-CANCELING PERSONAL AUDIO DEVICES
First Claim
1. A personal audio device, comprising:
- a personal audio device housing;
a transducer mounted on the housing for reproducing an audio signal including both source audio 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;
at least one microphone mounted on the housing for providing at least one microphone signal indicative of the ambient audio sounds and that contains a component due to the acoustic output of the transducer; and
a processing circuit that generates the anti-noise signal to reduce the presence of the ambient audio sounds heard by the listener, wherein the processing circuit implements an adaptive filter having a response that shapes the source audio and a combiner that removes the source audio from the at least one microphone signal to provide a corrected microphone signal, and wherein the processing circuit determines a relative magnitude of a source audio component of the acoustic output of the transducer present in the at least one microphone signal and the ambient audio sounds present in the at least one microphone signal, and wherein the processing circuit takes action to prevent improper adaptation of the adaptive filter in response to determining that the relative magnitude of the source audio component of the acoustic output of the transducer present in the at least one microphone signal to the ambient audio sounds present in the at least one microphone signal indicates that the adaptive filter may not adapt properly.
1 Assignment
0 Petitions
Accused Products
Abstract
A personal audio device, such as a wireless telephone, generates an anti-noise signal from a microphone signal and injects the anti-noise signal into the speaker or other transducer output to cause cancellation of ambient audio sounds. The microphone measures the ambient environment, but also contains a component due to the transducer acoustic output. An adaptive filter is used to estimate the electro-acoustical path from the noise-canceling circuit through the transducer to the at least one microphone so that source audio can be removed from the microphone signal. A determination of the relative amount of the ambient sounds present in the microphone signal versus the amount of the transducer output of the source audio present in the microphone signal is made to determine whether to update the adaptive response.
-
Citations
39 Claims
-
1. A personal audio device, comprising:
-
a personal audio device housing; a transducer mounted on the housing for reproducing an audio signal including both source audio 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; at least one microphone mounted on the housing for providing at least one microphone signal indicative of the ambient audio sounds and that contains a component due to the acoustic output of the transducer; and a processing circuit that generates the anti-noise signal to reduce the presence of the ambient audio sounds heard by the listener, wherein the processing circuit implements an adaptive filter having a response that shapes the source audio and a combiner that removes the source audio from the at least one microphone signal to provide a corrected microphone signal, and wherein the processing circuit determines a relative magnitude of a source audio component of the acoustic output of the transducer present in the at least one microphone signal and the ambient audio sounds present in the at least one microphone signal, and wherein the processing circuit takes action to prevent improper adaptation of the adaptive filter in response to determining that the relative magnitude of the source audio component of the acoustic output of the transducer present in the at least one microphone signal to the ambient audio sounds present in the at least one microphone signal indicates that the adaptive filter may not adapt properly. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. A method of countering effects of ambient audio sounds by a personal audio device, the method comprising:
-
adaptively generating an anti-noise signal to reduce the presence of the ambient audio sounds heard by the listener; combining the anti-noise signal with source audio; providing a result of the combining to a transducer; measuring the ambient audio sounds and an acoustic output of the transducer with at least one microphone; implementing an adaptive filter having a response that shapes the source audio and a combiner that removes the source audio from at least one microphone signal to provide a corrected microphone signal; determining a relative magnitude of a source audio component of the acoustic output of the transducer present in the at least one microphone signal and the ambient audio sounds present in the at least one microphone signal; and taking action to prevent improper adaptation of the adaptive filter in response to determining that the relative magnitude of the source audio component of the acoustic output of the transducer present in the at least one microphone signal to the ambient audio sounds present in the at least one microphone signal indicates that the adaptive filter may not adapt properly. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
-
-
27. An integrated circuit for implementing at least a portion of a personal audio device, comprising:
-
an output for providing an output signal to an output transducer including both source audio 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; at least one microphone input for receiving at least one microphone signal indicative of the ambient audio sounds and that contains a component due to the acoustic output of the transducer; and a processing circuit that adaptively generates the anti-noise signal to reduce the presence of the ambient audio sounds heard by the listener, wherein the processing circuit implements an adaptive filter having a response that shapes the source audio and a combiner that removes the source audio from the at least one microphone signal to provide a corrected microphone signal, and wherein the processing circuit determines a relative magnitude of a source audio component of the acoustic output of the transducer present in the at least one microphone signal and the ambient audio sounds present in the at least one microphone signal, and wherein the processing circuit takes action to prevent improper adaptation of the adaptive filter in response to determining that the relative magnitude of the source audio component of the acoustic output of the transducer present in the at least one microphone signal to the ambient audio sounds present in the at least one microphone signal indicates that the adaptive filter may not adapt properly. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
-
Specification