Just curious, when a missle is launched off a ship, can the entire crew hear it go off?
Yes, when a ship launches a missile, everyone on board knows it.
Unless you're on an aircraft carrier and launching a small sea sparrow missile, yes the crew would here it, at the very least hear about it. It's a pretty big deal to launch missiles on a ship or submarine.
Hell yes. And more than that. I participated in a couple of live shots, and every one was preceeded by a number of 1MC announcements warning the crew to stay the heck away from the missile launcher when we shoot the missile. Half the crew were involved in the process of shooting it and the other half were topside taking pictures. Everyone knows when one of those things go off.