I haven’t listened to much yet, but it seems to me to just be the guy reading. Slowly. I think I could cover this material much faster if I read it myself as I have no commute to contend with.
Professor Casey is just reading the Power Point presentation he created. They are provided separately with each lecture. It will still just be a guy reading but you an go as fast as you want. If you need a program to open them check out openoffice.org.