1. At basic we were issued these strange flanged ear plugs with an insertion tool. I'm not sure what they were called. Very uncomfortable, and guys would accidentally push them too far in.
2. When I went to Tikrit, Iraq with the Big Red One, we were issued the 3M plugs that 3M knew didn't work and now are getting a massive lawsuit brought before them.
3. I never got into a gun fight, but we had indirect attacks every day. Nobody had time to put earpro in, we were too busy running for the "bunkers".
4. I don't know about Armor specific operations. I do know they parked an Abrams next to the DFAC for a few weeks and fired scheduled H&I fire. I'm sure the guys would be smart enough to protect their ears during that. It's VERY loud.