Ask HN: Licensing for Research Papers

So I've been having a ton of fun with Tortoise-TTS [1], turning books into audio (currently on Heart Of Darkness). They sound spectacular and I'm thinking of putting up a blog with torrents to them just to share the love. Not trying to make a buck.

I also like to take my learning material and listen to it - to this end, I'm going to turn papers like Attention Is All You Need into audio for my own purposes. My question is what is ethically / legally involved in sharing them - i.e. should I. I can't see any license on the paper itself and the arxiv license only gives arxiv rights of any kind.

Anyone know where to look for this stuff? Google is less than helpful these days.

1 - https://github.com/neonbjb/tortoise-tts