I often read a book, and studied quite a bit while in med school. It was either review notes while on stand through the mid day, or not be able to go. I'll read through the mid day now, stop and go reading, nothing too serious.
I will have to admit to occasionally wearing a single ear bud when the Univ of Tennessee had a big football game in the mid day. Don't know if it ever had an effect on critters, but nice memories of fall leaves and Bama going down in flames a time or two. :D