The condition, which we talked about, is called somniloquy, more commonly known as sleep-talking. Speech while sleeping can be very soft or inaudible (like a mumbling noise) or it can be very loud, which, at times, can even escalate to shouting or howling. This is a common condition that many people experience while sleeping.
Is It A Bad Thing?
Not particularly, unless you are waking up the other person sleeping in your room at regular intervals...
Hope it helps...