Audiovisual Detection of Laughter in Human-Machine Interaction

Laughter is clearly an audiovisual event, consisting of the laughter vocalization and of facial activity, mainly around the mouth and sometimes in the upper face. However, past research on laughter recognition has mainly focused on the information available in the audio channel only, mainly due to the lack of suitable audiovisual data. Only recently few works have been published which combine audio and visual information and most of them deal with the problem of discriminating laughter from speech or other nonlinguistic vocalisations using presegmented data. There are very few works on audiovisual laughter detection from unsegmented audiovisual streams and have either been tested on small datasets or use coarse visual features. As a consequence, results are mixed and it is not clear to what extent the addition of visual information to audio is beneficial for laughter detection. In this work, we attempt to overcome the limitation of previous studies and investigate the performance of audiovisual fusion for laughter detection using audiovisual continuous streams from the SEMAINE database. Our results suggest that there is indeed an improvement in laughter detection with the addition of visual information which is dependent on the performance of the voice activity detector.