ArcEmu does not have any code to handle voice chat. There was a separate voice chat server that I never tested back in the days of Ascent.
I do not know about Mangos and TrinityCore, but a quick key word search of the emulator source code would tell you.
Mango itself doesn't exist anymore. Not sure what is with the repo, but the webpage no longer exists and my last update on this matter is, that the repo was hacked and unaccessible.
cMangos still exists though.
About Trinity, I don't remember it containing code about a voice chat application.