An audio processing device comprising at least one input transducer (M1, M2) for picking up a sound signal and converting it to at least one electric input signal (mic(n); IN1, IN2) and at least one output transducer for converting an electric output signal (u(n); OUT) to an output sound, a forward path being defined between the at least one input transducer (M1, M2) and the at least one output transducer, the forward path comprising • a signal processing unit (HA-DSP) for processing the at least one electric input signal (mic(n); IN1, IN2) or a signal derived therefrom and providing a processed output signal and • the audio processing device further comprising • a de-correlation unit (DEC; FS); and • an analysis path in parallel to all or a part of the forward path, the analysis path comprising • a feedback estimation system for estimating feedback from the at least one output transducer to the at least one input transducer and providing a corresponding feedback estimation signal (vh(n); EST1, EST2; EST), the feedback estimation system comprising an adaptive filter comprising a variable filter part (Filter; FIL1, FIL2) for filtering an input signal (OUT; u(n)) according to variable filter coefficients and an algorithm part (Algorithm; ALG), the algorithm part comprising an adaptive algorithm for dynamically updating said filter coefficients, • a control unit (CONT) for controlling said de-correlation unit (DEC; FS) and said adaptive algorithm (Algorithm; ALG), and • a correlation detection unit (ACD/XCD) for determining a) the auto-correlation of a signal of the forward path and providing an AC-value and/or b) the cross-correlation between two different signals of the forward path and providing an XC-value, wherein said de-correlation unit (DEC; FS) is located in the forward path and is adapted for de-correlating the electric output signal and the electric input signal (mic(n); IN1, IN2), and CHARACTERIZED IN THAT • the audio processing device comprises an audibility sensor configured to identify artefacts in a signal of the forward path and to estimate whether or not a given artefact is audible, wherein the audibility sensor is made dependent on the AC-value and/or the XC-value, • the control unit is configured to base or influence its control of said de-correlation unit (DEC; FS) and said adaptive algorithm (Algorithm; ALG) on said AC-value and/or said XC-value, and • wherein the control unit is configured to control the de-correlation unit and an adaptation rate of the adaptive algorithm to minimize audibility of artefacts. • a signal processing unit (HA-DSP) for processing the at least one electric input signal (mic(n); IN1, IN2) or a signal derived therefrom and providing a processed output signal and • the audio processing device further comprising • a de-correlation unit (DEC; FS); and • an analysis path in parallel to all or a part of the forward path, • a feedback estimation system for estimating feedback from the at least one output transducer to the at least one input transducer and providing a corresponding feedback estimation signal (vh(n); EST1, EST2; EST), the feedback estimation system comprising an adaptive filter comprising a variable filter part (Filter; FIL1, FIL2) for filtering an input signal (OUT; u(n)) according to variable filter coefficients and an algorithm part (Algorithm; ALG), the algorithm part comprising an adaptive algorithm for dynamically updating said filter coefficients, • a control unit (CONT) for controlling said de-correlation unit (DEC; FS) and said adaptive algorithm (Algorithm; ALG), and • a correlation detection unit (ACD/XCD) for determining a) the auto-correlation of a signal of the forward path and providing an AC-value and/or b) the cross-correlation between two different signals of the forward path and providing an XC-value, • the audio processing device comprises an audibility sensor configured to identify artefacts in a signal of the forward path and to estimate whether or not a given artefact is audible, wherein the audibility sensor is made dependent on the AC-value and/or the XC-value, • the control unit is configured to base or influence its control of said de-correlation unit (DEC; FS) and said adaptive algorithm (Algorithm; ALG) on said AC-value and/or said XC-value, and • wherein the control unit is configured to control the de-correlation unit and an adaptation rate of the adaptive algorithm to minimize audibility of artefacts.