Originally posted in the old Capture website, at capture.beyondunreal.com, now defunct. I had a copy in my backups.
Voice Communication
One of the most interesting new features to be added in ut2k4 is the built-in voice com system. Previously, only clans and other organised groups of players tended to use 3rd party communication programs with the normal player relying mainly on binds. Now everyone can instantly get on their mics and begin barking orders or talking smack to everyone in the game. The main benefit of this being that you can tell anyone who can understand the language you are using exactly what, when and how you are going to go about winning the map without having to bind keys to a limited set of descriptions. If used constructively, to talk about what you are doing instead of complaining about how your team is rubbish and that's why you lost or how good their mother is in bed, teamwork can be made much easier.
Basics
Firstly, head into the audio options and make sure you've got the voice settings configured how you need them. Take into account your bandwidth when deciding on the quality settings and be sure to tweak the volumes until you can hear other people and they can hear you, you'll have to use the windows volume controls for your mic volume settings.
The default key setting is as follows:
F - Hold this down to talk on your mic
I - Toggles from your current channel to teamchat and back again
O - Toggles from your current channel to local and back again
P - Toggles from your current channel to public and back again
You can also change channels using the menu the V key brings up, option 1 is voice com.
The channel toggle keys (I,O and P) must be held down while you also hold F to speak into your mic in order for your speech to go through to the channel you want. Personally, I find this to be a little tricky when I'm in the middle of a game so I changed them to be single press channel switches. You can do this by going into the User.ini file in the system folder and removing the "|OnRelease SpeakLast" part from the chat toggle aliases, they are numbers 29,30 and 31 in the list at the start of the ini. Just remember which channel you are speaking on, you don't want to be telling everyone on the other team what your team is up to by speaking in public.
Remember, if you have altered any of the voice binds without thinking about it and need to get them back you can always find the line to re-enter in the DefUser.ini.
If you've got a mic then use it! I'm sure your voice can't be that freakish that you don't want people to hear it. If everyone in the team hooks up on the coms then you can all go rolling up to your enemy's nodes/flag/objectives in a group and deliver them a beating.
CTF
Now I will just give some brief advice on what kinds of comments are helpful to your team mates from various positions in capture the flag.
Defence
When defending, it is important to keep your flag carrier and support players updated on the safety of your base. If there are enemies in your flag room when the carrier is coming back to cap then they need to be told to proceed with caution. It is also good to call for backup from the midfield players when you feel that you are about to be overrun by the enemy.
Midfield
Voice chat is a great way to let your defenders know which way enemies are approaching the flag room from. No more binds, but a brief snippet of chat to tell them exactly where you saw them enter. This is invaluable information as it allows the defence to position itself according to where the threat will come from. Quick thinking on their part can give them the drop on attackers who might otherwise have a much greater chance of winning a firefight with them. Remember, forewarned is forearmed.
Attack
If you can give an accurate comment about your current location and path then it is much more likely that your team will be there to meet you and provide backup as you head home with the flag. Setting up attacks is much easier over voice chat as well, tell your team mates where you are meeting up and which way you are going in and off you go.
ONS and Assault
Both of these gametypes require a similar style of communication, namely the identification of which target you are aiming at and how you are going to go about hitting it. Use the voice chat to co-ordinate your attempts at various objectives so that your team doesn't approach in dribs and drabs to be easily picked off by the enemy. If you talk on team and get people who are respawning to hold back and team up you will have a much better chance of success.
In Onslaught, saying which vehicle you are taking, where you are taking it from and where you are going with it is a good way to let your team know what kind of support to expect at critical points. Telling them your starting location allows them to know that you are able to travel with them if the are nearby, gaining you gunners for the hellbender or tank or getting your team out to hotspots quicker on the manta's wings.
The most powerful use for the voice chat in assault is to change the tactics you are using to capture a particular objective in mid-game. If your enemies are defending in a particular way that leaves other objectives vunerable then describing the weakness and how you wish to exploit it allows your team a quick shift in focus. Catching the opposition napping feels pretty good when you hit objectives in quick succession with no resistance.
The addition of voice communication to the unreal engine is a very welcome one that gives a much greater scope for teamwork in public games than ever before. Hopefully it will be accepted as the norm by the communitry to talk to each other during games to help each other out and not just to endlessly smack talk on insta dm servers.