I. Introduction
Separation of sound sources with time-varying mixing properties, caused by the movement of the sources, is a relevant research problem for enabling intelligent audio applications in realistic operation conditions. These applications include, for example, speech enhancement and separation for automatic speech recognition [1] especially when using voice commanded smart devices from afar [2]. Another emerging application field includes immersive audio for augmented reality [3] which requires modification of the observed sound scene for example by removing sound sources and replacing them with augmented content. Separation of non-speech sources can be also used to improve sound event detection in multi-source noisy environment [4] . Most existing works related to sound separation are assuming stationary sources, and not many blind methods have targeted the problem of moving sound sources despite its high relevance in realistic conditions.