In most MMORPG are fantasy based and global voice chat makes no reasonable sense, yet many have it. However In Star Trek, voice chat makes perfect sense and it is not there.
Few people type to talk in the game, mainly because they need their keyboard to ply their ship, or move around. Also since there is no auto attack, so to talk means stop everything while you do it. Thus not much chatter, and next to impossible to use typed text to coordinate the very fast paced combat.
I built in voice chat for groups would do wonders for player interaction on the game.
Though I have found that other games that built voice chat into the system did not work right. WoW voice chat is awful and no one uses it because it crashes so much. DDO also has a voice chat system that is almost as bad as WoW's.
Voice chat in LOTRO and DDO is fine if the player takes the time to actually set up their mics. Sadly though it a little work to set up to work correctly in vent and in-game, but once done it works great. I often run both in those games, Vent for Kinship/tribe and in Game for groups.
I will say Vent is better though and when we have a kinship only fellowship we use it.
I am not sure of the licensing and technology behind it, but is sorely missing. Audio communication is featured in Star Trek more than phasers.