Method to reduce artifacts in algorithms with fast-varying gain

摘要

METHOD AND DEVICE FOR REDUCING ARTIFACTS IN AUDIO PROCESSING ALGORITHMS WITH FAST-VARYING GAIN 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. One object of the present application is to improve and/or effect a user's perception of a sound signal, which has been subject to one or more audio processing algorithms. Artifacts are reduced 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; optionally 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 audio processing systems, e.g. public address systems, listening devices, e.g. hearing instruments.