It shoots testosterone levels through the roof, which in turn promotes aggressive behavior. Loud talking can easily be associated with the drive and agressiveness that these guys (tools) are exhibiting. Usually, if guys are really toolbags and put on a few pounds of water from the steroids they are misusing, they will tend to be all loud in the gym because they feel big and stuff. It's the quiet guy in the corner with an IPOD on thats ripped out of the frame and pounding out heavy sets that is really getting the attention from the girls.
Say something sarcastic to them like: speak up a little guys, so the people across the street can hear you better.
