Stacy Horn's "Cyberville" is a memoir about running a New York City based BBS that ran through the 1990s and early 2000s. She talks about having phone calls with new users and walking them through what they need to know about the place. Hugely influential on my thinking.
https://www.grandcentralpublishing.com/titles/stacy-horn/cyberville/9780446572064/
(Many thanks to @theuniverse for turning me on to this book btw)
@darius @theuniverse yesss! voice verification was the DEFAULT setting for many BBS host programs