1. Signal Processing and Speech Communication Laboratory, Department of Electrical Engineering, Graz University of Technology, Inffeldgasse. 16c, A-8010 Graz, Austria
2. Computing, Electronics and Communication Technologies, Faculty of Engineering, University of Deusto, Bilbao, Spain
3. Acoustic Technology, Department of Electrical Engineering, Technical University of Denmark (DTU), Building 352, Ørsteds Plads, DK-2800 Kongens Lyngby, Denmark