An integrated circuit for implementing at least a portion of a personal audio device, comprising: an output for providing a signal to a transducer (SPKR) 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 (SPKR); a reference microphone input for receiving a reference microphone signal (ref) indicative of the ambient audio sounds; an error microphone input for receiving an error microphone signal (err) indicative of the output of the transducer (SPKR) and the ambient audio sounds at the transducer (SPKR); and wherein the integrated circuit is characterized in that it further comprises a processing circuit comprising: an adaptive filter having a response that generates the anti-noise signal from the reference microphone signal (ref); 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 signal from the source audio signal; a biasing portion (46, 34C) that generates a scaled anti-noise signal by applying a scaling factor (k), wherein the scaling factor (k) has a value between 0 and 1, and the response of the secondary path estimate filter to the anti-noise signal; and a coefficient control block that shapes the response of the adaptive filter in conformity with the reference microphone signal (ref) and a modified playback corrected error signal by adapting the response of the adaptive filter to minimize the ambient audio sounds in the error microphone signal (err), wherein a playback corrected error signal is based on a difference between the error microphone signal and the secondary path estimate signal and wherein the modified playback corrected error signal is based on a difference between the playback corrected error signal and the scaled anti-noise signal. an output for providing a signal to a transducer (SPKR) 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 (SPKR); a reference microphone input for receiving a reference microphone signal (ref) indicative of the ambient audio sounds; an error microphone input for receiving an error microphone signal (err) indicative of the output of the transducer (SPKR) and the ambient audio sounds at the transducer (SPKR); and wherein the integrated circuit is characterized in that it further comprises a processing circuit comprising: an adaptive filter having a response that generates the anti-noise signal from the reference microphone signal (ref); 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 signal from the source audio signal; a biasing portion (46, 34C) that generates a scaled anti-noise signal by applying a scaling factor (k), wherein the scaling factor (k) has a value between 0 and 1, and the response of the secondary path estimate filter to the anti-noise signal; and a coefficient control block that shapes the response of the adaptive filter in conformity with the reference microphone signal (ref) and a modified playback corrected error signal by adapting the response of the adaptive filter to minimize the ambient audio sounds in the error microphone signal (err), wherein a playback corrected error signal is based on a difference between the error microphone signal and the secondary path estimate signal and wherein the modified playback corrected error signal is based on a difference between the playback corrected error signal and the scaled anti-noise signal. an adaptive filter having a response that generates the anti-noise signal from the reference microphone signal (ref); 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 signal from the source audio signal; a biasing portion (46, 34C) that generates a scaled anti-noise signal by applying a scaling factor (k), wherein the scaling factor (k) has a value between 0 and 1, and the response of the secondary path estimate filter to the anti-noise signal; and a coefficient control block that shapes the response of the adaptive filter in conformity with the reference microphone signal (ref) and a modified playback corrected error signal by adapting the response of the adaptive filter to minimize the ambient audio sounds in the error microphone signal (err), wherein a playback corrected error signal is based on a difference between the error microphone signal and the secondary path estimate signal and wherein the modified playback corrected error signal is based on a difference between the playback corrected error signal and the scaled anti-noise signal.