Friend thinks screaming is funny?

My friend think its hysterical to scream. Not only does she find screaming herself funny, but hearing other people scream. She is 18, and records herself screaming and then begs me to listen to the recordings and laughs hysterically for hours at it. This is not surprising to me considering her older brother records himself farting. They also tell me they have recorded their screams and farts since they were children so they pretty much have a box set full of their screams and farts throughout the years. This is a very annoying thing because whenever someone is being funny or laughing at something, my friend will scream, everyone will jump up and get irritated, and then she will laugh about it. I can't understand why she finds screaming so funny, she even laughs when babies are crying. She is a great friend but its so irritating! Has anyone else ever heard of finding screaming amusing?