Protip: If you played FH1, the voices are the exact same.
I'm sure you came to recognize at least a few of the commands by sound without having to look at the typed out message, right? Well they're the same ones. Also, play for a bit and you'll recognize the commands by sound, especially if you use them yourself and listen to what your character is saying. Finally, Commanders and Squad Leaders still put the typed out message up, so if you really need the visual medium, maybe load up a local game, make yourself a squad leader, and start shouting commands. After a while, stop begin SL and see if you can still associate the vocals with the correct command.
Or, you can just remember that frantic, panicked voices either mean "Medic!", "Grenade!" or "Fire in the Hole!" since those are the only somewhat useful commands that grunts may be using. SLs might use the other ones, but you a text representation from them. Although, the "Pickup" and "Wait!" commands might be good to memorize. And anything that sounds like a battle cry is probably a "Charge!" or "Go, go, go!" command.
