Okay, posted. Boyd and David might have heard something... A sharp pop, followed by a pair of pops about a second apart a couple or three seconds later. It just depends, as Chris downed a couple walkers. 

I don't remember if suppressors in the tv series are movie-quiet or not... but I'm going with somewhat realistic. A suppressor does not make things whisper quiet (unless a big one is on the end and it's a small caliber, and probably subsonic ammo) but it does reduce the noise a lot, and changes the sound some. If the series uses the movie stype... I'll switch. I'm not above having fun.