Sounds such as coughing, slurping, or the crinkle of a bag of chips can cause them to feel distressed, leaving them anxious and angry. It’s a condition called misophonia.
With me, it's somebody slurping their food, smacking their lips while eating, or popping their gum. I don't know if it's that misophonia bullshit or the fact that I was raised with manners, I don't know. Or care. But if you want to be rude, I'll be rude too - I'll get up and walk away from the table if somebody is smacking their lips or slurping their food.