Smacking lips. Forks on plates. Gum chewing.
These types of sounds are heard every day, and many of us simply can't stand them and it's not just because they're annoying. If you are one of those people who gets put on edge from hearing certain sounds you might have a brain condition called Misophonia.
Misophonia causes extreme reactions of anger, anxiety or even full-out rage and it's triggered exclusively by sounds. Common sounds like eating, clearing a throat or sniffling could cause you to lose your mind.
A study at Newcastle University mapped people's brainwaves and their responses to what they described as trigger sounds. The maps showed the people had an abnormality in emotion control when they heard certain sounds.
While not dangerous, Misophonia can lead to anti-social behavior, simply because a sufferer can't stand to be around other people.
If nothing else at least this gives you a good medical reason to ask someone to start chewing with their mouth closed.
Check out Newcastle University's video study here: