Someone mentioned that in high noise situations you hear better with "ear protection", that is, wax, cotton, or other ear plugs in. This is true, and while serving as a flight surgeon in the Air Force we were instructed that when flying in really noisy aircraft (such as the C130 before they redid the props) to wear our ear plugs. I found that indeed, with the plugs in I could hear the fellow next to me shouting, better than when he was shouting and I had no ear plugs in.