Hearing protection is an often over-looked safety issue. Everyone has their ear protection on at the range. Not too many people think about it in connection with actually having to use a gun to defend their homes however. I heard someone say on Guns and Ammo TV the other night that if you ever fire a centerfire rifle inside a closed room, you won't do it a second time. The segment was focused on suppressors for home defense use. It's a great idea but suppressors require a$200 tax stamp as i recall in addition to the hefty cost. I don't see many people rushing out to get them. My question is, what is the biggest caliber you can safely shoot indoors without ear protection. Is it realistic to put on acoustic-canceling headphones in an emergency?