The importance of laughing in your face: influences of visual laughter on auditory laughter perception

Hearing the sound of laughter is important for social communication, but processes contributing to the audibility of laughter remain to be determined. Production of laughter resembles production of speech in that both involve visible facial movements accompanying socially significant auditory signals. However, while it is known that speech is more audible when the facial movements producing the speech sound can be seen, similar visual enhancement of the audibility of laughter remains unknown. To address this issue, spontaneously occurring laughter was edited to produce stimuli comprising visual laughter, auditory laughter, visual and auditory laughter combined, and no laughter at all (either visual or auditory), all presented in four levels of background noise. Visual laughter and no-laughter stimuli produced very few reports of auditory laughter. However, visual laughter consistently made auditory laughter more audible, compared to the same auditory signal presented without visual laughter, resembling findings reported previously for speech.