You will not suffer permanent hearing damage from a one-time unprotected exposure to home defense gunfire. In fact, many people in true life or death situations experience auditory exclusion syndrome and don't conciously hear the gunfire at all.
Don't listen to this foolish advice. It took a SINGLE shot for me to suffer permanent hearing damage. See my previous post.
As far as auditory exclusion, your brain may not register the sound of the shot but your ears still take the full force of it regardless of if you remember hearing it or not.
Before you give advice, know what your talking about.
As Brian can attest, Tinnitus is no fun.
Just in case people don't know how this works, there are little tiny microscopic hairs in your ear that pick up sound and send signals to your brain. When your ears are exposed to loud noises these hairs are knocked over and damaged. Picture stepping on grass, it gets pushed down but will eventually spring back up. Repeatedly step on that same spot of grass or put something heavy enough and it will stay flat. Well when these hairs are permanently damaged or die, they are no longer sending signals or the correct signals. These false signals from the dead hairs result in hearing a constant ringing. There is currently no cure for tinnitus, and probably wont be one untill stem cell research becomes more common.