Disgust expressive speech : the acoustic consequences of the facial expression of emotion

This study investigated how the facial expression of disgust may affect the acoustics of speech. In terms of a pathogen avoidance mechanism, the expression of disgust would seem to require speech to be produced with a smaller mouth opening than neutral speech, hence lowering the formant frequencies. This hypothesis was tested by comparing how lip configuration (i.e., height, width and size of the lip area), fundamental frequency (F0) and the formants (F1 and F2) of the vowels ([Figure presented]) changed when produced in neutral or disgust expressions. The vowels were extracted from 50 Cantonese sentences spoken by 10 (5 male) talkers; produced once in disgust and once more in a neutral tone of voice. The results support the notion that the facial expression of emotions may have a role in shaping the acoustic properties of the vocal expressions of emotions. Mixed effects logistic regression models revealed that in disgust, vowels were produced with lower lip height, lower F1, F2, and higher F0 than neutral speech.