An integrated circuit for implementing at least a portion of a personal audio system, comprising: a first output adapted to provide a first output signal to a first earspeaker (SPKR1) including both first source audio for playback to a listener and a first anti-noise signal for countering the effects of ambient audio sounds in a first acoustic output of the first earspeaker (SPKR1); a second output adapted to provide a second output signal to a second earspeaker (SPKR2) including both second source audio for playback to a listener and a second anti-noise signal for countering the effects of the ambient audio sounds in a second acoustic output of the second earspeaker (SPKR2); at least one microphone input adapted to receive at least one microphone signal indicative of the ambient audio sounds; and a processing circuit (20, 30) configured to generate the first anti-noise signal from the at least one microphone signal using a first adaptive filter to reduce the presence of the ambient audio sounds at the first earspeaker (SPKR1) in conformity with the at least one microphone signal, wherein the processing circuit (20, 30) is further configured to generate the second anti-noise signal from the at least one microphone signal using a second adaptive filter to reduce the presence of the ambient audio sounds at the second earspeaker (SPKR2) in conformity with the at least one microphone signal, characterized in that the processing circuit (20, 30) is configured to determine a first degree of coupling between the first earspeaker (SPKR1) and an ear of the listener and to determine a second degree of coupling between the second earspeaker (SPKR2) and another ear of the listener, and the processing circuit (20, 30) is further configured to halt an update of coefficients of both the first adaptive filter and the second adaptive filter in response to detecting that the first degree of coupling indicates that the first earspeaker (SPKR1) is loosely coupled to the ear of the listener or that the second degree of coupling indicates that the second earspeaker (SPKR2) is loosely coupled to the other ear of the listener, while continuing to generate the first anti-noise signal and the second anti-noise signal. a first output adapted to provide a first output signal to a first earspeaker (SPKR1) including both first source audio for playback to a listener and a first anti-noise signal for countering the effects of ambient audio sounds in a first acoustic output of the first earspeaker (SPKR1); a second output adapted to provide a second output signal to a second earspeaker (SPKR2) including both second source audio for playback to a listener and a second anti-noise signal for countering the effects of the ambient audio sounds in a second acoustic output of the second earspeaker (SPKR2); at least one microphone input adapted to receive at least one microphone signal indicative of the ambient audio sounds; and a processing circuit (20, 30) configured to generate the first anti-noise signal from the at least one microphone signal using a first adaptive filter to reduce the presence of the ambient audio sounds at the first earspeaker (SPKR1) in conformity with the at least one microphone signal, wherein the processing circuit (20, 30) is further configured to generate the second anti-noise signal from the at least one microphone signal using a second adaptive filter to reduce the presence of the ambient audio sounds at the second earspeaker (SPKR2) in conformity with the at least one microphone signal, characterized in that the processing circuit (20, 30) is configured to determine a first degree of coupling between the first earspeaker (SPKR1) and an ear of the listener and to determine a second degree of coupling between the second earspeaker (SPKR2) and another ear of the listener, and the processing circuit (20, 30) is further configured to halt an update of coefficients of both the first adaptive filter and the second adaptive filter in response to detecting that the first degree of coupling indicates that the first earspeaker (SPKR1) is loosely coupled to the ear of the listener or that the second degree of coupling indicates that the second earspeaker (SPKR2) is loosely coupled to the other ear of the listener, while continuing to generate the first anti-noise signal and the second anti-noise signal.