When I play Dirty Bomb, I would like to be able to differentiate between my team and the enemy team by the sounds people make. In W:ET this was really easy as both teams mostly had their own guns (and if an enemy picked up a gun of your team, they could quite surprise you). I seem to remember SD once mentioned guns from one team would have a more clean sound, while the guns of the other team would be more rusty. Right now I don’t notice it at all.
Overall, I have a very hard time deciphering anything useful from the sounds of gun play in the game. It seems hard to determine where sounds are coming from, and the different gun sounds sound too much alike to really distinguish easily between mercs (as far as they have different guns) and teams.
It also seems footsteps are not easy to hear. In W:ET, you could easily take down 2-3 enemies by camping a corner and rushing in at the right moment based on the footsteps enemies make. In DB, I have not experienced such a thing at all.
