A similar idea had often crossed my mind. I even tried sleeping one night with those little disposable foam ear plugs in my ears...the idea being that although they don't totally block sound, they at least dampen it.

Sounded fine in theory, but in practice, they came out of my ears during the night. So that sorta nixed that idea.

Firing a large caliber pistol in a small room without ear protection is brain numbing experience, believe me, but as someone else says, it's lots better to have hearing loss than life loss.