You shouldn't talk loudly around people because it's rude.
Mary and Johah are going to the movies with friends.
Mary wants  Jonah to pass her the popcorn.
Mary whispers to the friend beside her to ask Jonah for popcorn.
Mary shouts down the aisle to Jonah for the popcorn.
Jonah passes Mary the popcorn and everyone enjoys the film.
Mary is asked by the ushers to quiet down, and she is embarrassed.