I listen to them while I'm driving which is about an hour a day. I'm a first year so I just use them for exams. I'm an auditory learner, so for me, they work. I've listened to biochem, anatomy, physiology, and am starting neuro. My school library has copies in both tape and cd versions so I don't know if they are worth the price. I just check out a different one when I return one. But, I'm one of the only ones who seems to sign them out so I'm not sure how useful they are to other students. Good luck however you study.