For the Linux using UT2004 users out there looking to get text-to-speech working might want to download and install speechd.
Once installed, you’ll need to edit the UT2004.ini file in your /ut2004/System directory. Locate the line containing “TextToSpeechFile=” and add “/dev/speech”. You’ll need to run speechd prior to starting UT2004, of course, and then enable the text-to-speech feature within the in-game settings.
Unfortunately, there seems to be no clean way to stop the speechd service, so you’ll probably have to do a “killall speechd” as well as “killall festival-server”.