What are the best oral (audio) materials for introductory instructional learning of programming, computer science, mathematics etc, with no visual presentation?  I'm thinking of the huge population of us driving for many hours every day and working in gyms etc..  There are lists like  but they tend not to be instructional or introductory.   Do you know of any audio books that actually "speak" the code?  I feel there has to be a huge market for this, but it is very difficult to find much of anything.