I've tried this on Linux+Firefox, but it doesn't sound very good yet, I'm afraid.
Yeah, it's using OS's voices and usually they are quite robotic. But it's still quite useful if you want to upload a long text into your brain.
I'm also using Narrator in my HN reader (no settings for voice right now though, except localStorage['cfg-narrator-rate'] via devtools):
https://tts.cns.wtf/
https://github.com/python273/tts-app