Vocalisations of Disgust

Consider hearing someone exclaim, "Ew! Yuck! Ugh!" These sounds let you know that a person is experiencing disgust. And that disgust is often experienced when people see, smell, or touch things that, over evolutionary history, have been sources of infectious disease, like vomit or spoiled food. Disgust isn't a one-size-fits-all emotion, though. It can also arise in reaction to moral transgressions. Think of the stomach-twisting feeling you might have gotten upon learning about a company mistreating its employees, or upon seeing a stranger mistreat his dog. These are instances of moral disgust. Our research tested whether people make different sounds when expressing disgust toward pathogen risks versus immoral acts. Using machine learning methods, we found that pathogen and moral disgust vocalisations are acousticlly different. Further, listeners can differentiate these two types of disgust vocalisations. This study sheds light on the fascinating world of human emotions and communication, showcasing how computational methods might help us understand expressions of disgust. So, the next time you hear an "Ew!" or "Yuck!" remember, there's a lot more to these sounds than meets the ear!