People who are annoyed by the sound of chewing are less likely to be vexed if they think it is made by an animal or other non-human source, rather than a person.
“I think most people can relate to having some level of aversion to certain sounds,” says Miren Edelstein at the University of California, but people with severe cases are said to have a condition called misophonia. “Individuals with misophonia experience aversion that is so severe and debilitating that it has a major impact on their well-being …
Source: Humans - newscientist.com