8-12 are my lighter reads. Some of my favorites are 25-30.
I do do double speed, so I wonder if that ticks twice as fast on there. But 15 hours a month is pretty bad.
Edit: I just got an email from audible. I've listened to ~20900 minutes (348 hours) in 9 months (38.5/month) on there this year, and I've used Scribd and Libby way more. Obviously I'm not typical, and supporting me isn't reasonable. But since they sent that the same day I made this post I thought I'd add it.