To enable, you can just put a check mark there in the lobby:
https://zero-k.info/mediawiki/Game_Lobby#GameThen you'd want to start a game and in the game menu check the volume setting for it because it can be too low to hear even when it works. One cool thing about it is that if you have multiple voices installed, it will select them at random for different people, so everyone can have a different voice. Must be English voices or it won't work. It also has a limitation that it can't say anything other than Latin alphabet (even numbers are filtered out).
Galamesh: It still does that. Or used to before the last update. I was actually planning to override this and filter out the "I choose" thing. I think it would actually make more sense for the message to be "<Player X> chooses <Com Name>" instead of "I choose Com Name." Might sound less annoying that way, too. The text change should be a trivial fix for someone who can just upload a file to the main repository.
BTW, I don't see it in the list of widgets. I actually put a copy of it (snd_text_to_speech.lua) in the LuaUI widgets folder, and it still doesn't show up. Logs suggest that it does load though, and I don't see anything else about it there, which suggests to me that the widget is still loaded, but the sound is either not generated or is routed somewhere into oblivion.