The number of bullet hit sounds that play is equal to the number of hits you take, even if you enter the tower quickly. Before, lag was unaccounted for and if someone absolutely mauled you with .50s but your connect was a little slower, you'd hear one hit and be in the tower. This spawned "OMG 1 .50 killd meh plane!!!" posts until HTC decided to not stop the sounds when you enter the tower.
Long story short, if you can count really fast, you hear every bullet hit you as long as your game doesn't crash or something.