Matt Campbell on Nostr: Pretty much not at all. I've listened to audiobook versions of non-fiction books that ...

Pretty much not at all. I've listened to audiobook versions of non-fiction books that probably do have references, but they're not mentioned by the narrator. That's for commercial audiobooks. Recordings made specifically for blind people, at least here in the U.S. by the National Library Service talking book program and Recording for the Blind (now Learning Ally), were better about this, at least when I was in high school and college.