A method and device reduce artifacts in an audio processing algorithm for applying a time and frequency dependent gain to an input audio signal. The method provides a time frequency representation of an input audio signal comprising a number of frequency bands; applies an audio processing algorithm providing an estimated algorithm output signal; determines for each frequency band a difference between a value of the estimated gain signal at a given time and at a preceding time; averages the difference over a predefined time; provides a confidence estimate based on the time averaged difference, the said confidence estimate being relatively low in case said time averaged difference is above a predetermined threshold level and relatively high in case said time averaged difference is below a predetermined threshold level; and optionally applies the confidence estimate to the noise reduced output signal thereby providing an improved algorithm output signal.