A phonetic analysis of natural laughter, for use in automatic laughter processing systems

In this paper, we present the detailed phonetic annotation of the publicly available AVLaughterCycle database, which can readily be used for automatic laughter processing (analysis, classification, browsing, synthesis, etc.). The phonetic annotation is used here to analyze the database, as a first step. Unsurprisingly, we find that h-like phones and central vowels are the most frequent sounds in laughter. However, laughs can contain many other sounds. In particular, nareal fricatives (voiceless friction in the nostrils) are frequent both in inhalation and exhalation phases. We show that the airflow direction (inhaling or exhaling) changes significantly the duration of laughter sounds. Individual differences in the choice of phones and their duration are also examined. The paper is concluded with some perspectives the annotated database opens.