Not piracy, but if you're in the US and get a library card, you can use the Libby app, which has tons of free audiobooks on demand. Definitely worth it, imho. You can download for offline use easily too, which makes it excellent for travel.
Piracy? I've been converting my epubs into html files and then using the edge browser's excellent voice to text to read it out to me, but that's my own special brand of insanity.