Method to reduce artifacts in algorithms with fast-varying gain

摘要

The application relates to a method of reducing artifacts in an audio processing algorithm for applying a time and frequency dependent gain to an input audio signal. The application further relates to an audio processing device. The object of the present application is to improve a user's perception of a sound signal, which has been subject to one or more audio processing algorithms. The problem is solved in by providing a time frequency representation of an input audio signal comprising a number of frequency bands; applying an audio processing algorithm, e.g. a noise reduction algorithm, providing an estimated algorithm output signal; determining for each frequency band a difference between a value of the estimated gain signal at a given time and at a preceding time; averaging the difference over a predefined time; providing a confidence estimate based on the time averaged difference, 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; applying said confidence estimate to said noise reduced output signal thereby providing an improved algorithm (e.g. noise reduced) output signal. An advantage of the present invention is that it provides a tool to reduce artifacts in algorithms for processing an audio signal in a time-frequency representation (e.g. noise reduction or speech processing algorithms). The invention may e.g. be used for the audio processing systems, e.g. public address systems, listening devices, e.g. hearing instruments.