At work today I'm showing Chris how to run the front part of a machine while Patricia is running the back. I hear a shout and look over at Patricia to see what's gone wrong with her end of the machine. She's running the machine like nothing's wrong so I start looking around to see where the shout came from. Chris asks, "What's wrong?" "Someone yelled something. There's a problem somewhere." Patricia looks over and shrugs - nothing wrong on her end, she didn't shout. "It must have been the voices in my head again," I say. Wade pipes up from where he's doing the paperwork, "Those were pretty loud voices. I heard it too."