Acoustic event detection in meeting-room environments

Acoustic event detection (AED) aims at determining the identity of sounds and their temporal position in the signals that are captured by one or several microphones. The AED problem has been recently proposed for meeting-room or class-room environments, where a specific set of meaningful sounds has been defined, and several evaluations have been carried out (within the international CLEAR evaluation campaigns). This paper reports some work in AED done by the authors in that framework, and particularly presents the extension to the difficult problem of detecting overlapped sounds. Actually, temporal overlaps accounted for more than 70% of errors in the real-world interactive seminar recordings used in CLEAR 2007 evaluations. An attempt to deal with that problem at the level of models using our SVM-based AED system is reported in the paper. The proposed two-step system noticeably outperforms the baseline system for both an artificially generated database and a real seminar recording database. The databases and metrics developed for the CLEAR 2007 evaluations are also described. Finally, a real-time AED system implemented in the UPC's smart-room using several microphones is reported, along with a GUI-based demo that includes also the output of an acoustic source localization system. (C) 2009 Elsevier B.V. All rights reserved.