one at a time, please

A friend of mine and I were just discussing our various pet peeves. The conversation started very shortly after I got off the phone with someone who was attempting to talk to me and cary on multiple other conversations at the same time on another medium. It bothers me when I am trying to hold a conversation and it begins to feel as if I'm speaking into a void. A conversation is based solely on interaction; when the second person is scarcely interacting it isn't a conversation, it's a monologue. If someone is telling you a story in a group do you also carry on five other conversations or do you listen to the story? I don't see how it's different.