wake the dead

Wake the dead is a phrase which means to be so loud that you would be waking people who are dead, the most soundly people, or sleepers. It does not literally mean your volume is going to wake people who are dead but a way to exaggerate exactly how loud you are being that you mine as well be waking up people who are sleeping so soundly that they are practically dead. It is most commonly said to someone as a way to convince them to speak in lower volumes.