Well that's just freaking brilliant. A lot of games lose sound quality because they are stacking the same sound on top of itself and that's why you lose clarity.
"-The Start is the initial attack; it’s the first shot fired and this sample always stays the same.
-The Middles are the tiny sections of each shot firing, broken up into pieces.
-The Ends are the tails of the final shot in a burst; like the Starts, these samples always stay the same.
Using clever code magic, the game checks if the player is firing at any given time and dynamically assembles the firing sound from the above elements. This playback method allows for an incredible amount of variation because we can dynamically assemble the Middles on the fly from our sample pool. It also retains any inherent mistiming in the source recordings, adding to the authenticity of the sound."
He explains it better than me :/