For the PM&R Oral Boards or for the Written Boards?
Either way, find a board review book with an eBook version available. Then play it on your phone using the many eBook-to-Audio apps/options. Works great. Did it back during residency for the SAE's and really helped.
Turn a Kindle Ebook into an Audiobook on iPhone | Genealogy Gems
Audiobook Reader | Turn any eBook into an Audiobook
The list goes on and on. Some of the apps that do this are rough, look for ones with good audio quality.
Good luck!
