The sound of disgust : how facial expression may influence speech production

![CDATA[In speech articulation, mouth/lip shapes determine properties of the front part of the vocal tract, and so alter vowel formant frequencies. Mouth and lip shapes also determine facial emotional expressions, e.g., disgust is typically expressed with a distinctive lip and mouth configuration (i.e., closed mouth, pulled back lip corners). This overlap of speech and emotion gestures suggests that expressive speech will have different vowel formant frequencies from neutral speech. This study tested this hypothesis by comparing vowels produced in neutral versus disgust expressions. We used our database of five female native Cantonese talkers each uttering 50 CHINT sentences in both a neutral tone of voice and in disgust to examine five vowels. Mean fundamental frequency (F0) and the first two formants (F1 and F2) were calculated and analysed using mixed effects logistic regression. The results showed that the disgust vowels showed a significant reduction in either or both formant values (depending on vowel type) compared to neutral. We discuss the results in terms of how vowel synthesis could be used to alter the recognition of the sound of disgust.]]