I have not seen the option lying around anywhere.

Players are incredibly hard for me to hear due to the amount of explosions, gunfire, et cetera that goes on. Perhaps an optional audio ducking or sound balancing system could be set in place so that players can adjust their volume and hear teammates.
The sliders could be separated and grouped accordingly so it cannot be abused by heightening audio such as footsteps. The sliders could be grouped according to game effects (explosions, gunfire and footsteps), weather or ambient music and finally voice chat.

Stezz.