In my humble opinion, cruising in the A-10 while listening to troops on the ground under SERIOUS ground fire really puts me in the cockpit. This is a really very interesting recording (From the Vietnam War), of US troops taking heavy ground fire from the enemy. I'm guessing A-10 pilots often here troops on the ground taking fire.   
Do have a listen !  
   
It really helps me with immersion.    
Thanks ! ;)