No voice chat. Too private for that. Real time text communications only.
I've used XMPP before for text chat. It was alright, but I just kept thinking why don't I just use IRC lol.
Doesn't https://nostrnests.com/ have voice chat? I haven't tried it, other than that it's a pickle, the other one I can think would suit you is XMPP's voice chat, but I haven't got it to reliably work, and I doubt you could get more people on it, it really sucks when there is so much people on the big tech side of the internet.
Discussion
I had the same problem with XMPP, and the OMEMO convinced me to make the switch, that and I remember reading the RFCs and liking some of them, but it really subjective.
You can always try Chachi and invite people (I've no idea how it works), now that I think about it I haven't tried Chachi either, I really need to get back to testing all the apps, they're all really cool.