I haven't played the "Special Operations" one, only the original "Operations" so I might be a bit off here, but.. the combat in Operations seemed pretty realistic. I don't mean to be rude, but have you ever been in "actual combat?" It sounds as though you were expecting something more along the lines of a SWAT team, which is very different from military tactics.
Also, it's possible that voice communication was left out on purpose. Generally in combat you don't want to say anything, because if you do, the enemy will hear you, at which point he or she will shoot you. Radios can be used if you're quiet, but that requires you to take at least one hand off your weapon, almost like, say, typing a message on a keyboard requires you to take at least one hand off your mouse.