This is a personal inquiry related to a person in my life who gets emotionally upset (states having feelings of aggression) whenever hearing open-mouthed chewing sounds. Could this be due to previous pairing with an aversive stimulus (something in the individual's past)? Or is this a common problem for some people? The extent to which it affects this person seems more extreme than I can understand, because this person has to either leave the room or put on headphones and loud music to avoid having to hear the sound, thus avoiding or prolonging the emotional reaction.
Any insight on this type of issue? Any suggestions for treatment? Systematic desensitization perhaps? I'd appreciate any kind of advice. Thanks!