It's not acceptable behavior to yell in other people's faces.
Matt asks his sister Jenny a question, but she doesn't hear him because she is listening to music on her headphones.
Matt wants to get Jenny's attention.
Matt calmly taps Jenny on the shoulder to get her attention.
Matt walks over to Jenny and yells loudly right in her face so that she hears him.
Jenny takes off her headphones and kindly asks what Matt needs.
Jenny is started and frightened by Matt's sudden shouting.