Audio Training Aids

Has anyone tried any audio training aids. I received an email that sells training materials for certifications, and I see they have a section for audio cd's. "Listen on your way to work", they advertise.
Any thoughts?
Any thoughts?
"We are the music makers, and we are the dreamers of the dreams." Willy Wonka
Comments
Its sketchy sometimes. For example, I have Scott Morris' CCIE R&S audio in the car. Its great for many things but there are times when you need to do the technical side via visual. My way of getting the most out of audio is to go for the video course, extract the audio, then do both. This way if I get confused with the audio, I can replay the video for better understanding. I've been doing this with the CISSP videos and its a better method for me but, your mileage may vary
I have a 50 min drive to work, so audio CD's are great in my situation. It makes the long and boring drive to and from work....well, more boring.