Most of us have been lucky enough to never witness someone's innards being spliced out of their body. Or someone's head being smashed into a wall. But in an action or horror film, we often believe that that's what actual violence sounds like. Deep in the Hollywood studios, sound editors have to create these sounds. How do they know what gruesome violence really sounds like? Brooke talks with Slate senior editor Daniel Engber who wrote about the battle between the real and created sound of violence.