It's entirely feasible that a player may use more than a visual cue to trigger a reactionary chamber (making this whole "gotta have good graphics" argument rather pointless). Back in ye olde beta shortly after chamber-blocking was implemented I learned to attempt chambers when I heard the distinct sound at the beginning of a swing. I stopped doing this because a large portion of players will feint by releasing their attack and cancelling, which plays the sound as well, but that doesn't mean it's not applicable still. The only other reason I stopped using that as my cue is because at the time almost all servers ran medium, so if my timing was spot-on for that sound cue I would swing too early and miss. On fastest it worked just fine. The sound plays from the very beginning of a swing, and even if you're relatively close if you had an excellent reaction time you could probably successfully chamber on sheer reaction using that sound as a cue.
Just sayin'.