First of all I HIGHLY doubt this would ever be implemented by the developers. Not only is something like real-time audio going to be pretty taxing on the servers, but its going to be impossible to moderate. And with the very strict rules regarding chatting on TLOPO, I wouldn't think they would implement anything that could have a possibility of being less "family friendly."
On another note. It's just a bad idea... I've never used the voice chat in any game that has it included. It turns out to be a cluster-cringe fest. And while it can be humorous for a while it quickly becomes annoying if you want to actually use it as it would be intended. Voice chatting is something that works better in small groups anyways. Friends pretty much know when to stop being annoying, random people will know when to stop but they just won't care.