For 18-year-old high school senior Ellie Rapp of Pittsburgh, the sound of her family chewing their dinner can be ... unbearable.
"My heart starts to pound. I go one of two ways. I either start to cry or I just get really intensely angry. It's really intense. I mean, it's as if you're going to die," she says.
Rapp has been experiencing this reaction to certain noises since she was a toddler. She recalls a ride home from preschool when her mother turned on the radio and started singing, which caused Rapp to scream and cry hysterically.