ABSTRACT
This chapter focuses on the acoustic features of laughter. Laughter, like many other human signal behaviours, is a multimodal display composed of visual and auditory signal components. Several studies of the acoustics of laughter have shown that laughter consists of sound patterns interrupted by short segments of silence. However, more studies have pointed to a high variability in laughter sounds. Elements might, for instance, get shorter and shorter towards the end of a laughter series, or the pitch might decrease from element to element. J. A. Bachorowski and M. J. Owren's study on the evaluation of voiced and unvoiced laughter was the first to show that listeners differ in their evaluation of laughter depending on the acoustic quality of the laughter elements. Like any other acoustic signal, laughter can be characterized by three physical domains: duration, frequency characteristics, including the fundamental frequency perceived as pitch and energy distribution over the signal.
