Thanks everyone for all the great feedback and suggestions. I have decided to go straight down the middle: audiobooks for assigned novels and audiobooks with simultaneous reading (when audio is available) for textbooks.
DS was having a meltdown about having to read 4 chapters of history and prepare Cornell notes for each chapter on Saturday ("It will take ALL DAY Mom!") when I went online and found an audio version of his history text. Problem solved! I was ecstatic to find this and he was able to complete the assignment is about 2 1/2 hours while reading and listening.
DS is even starting to think of audio as a solution for notetaking difficulties. The science teacher was talking too fast for dysgraphic DS to make notes of the test review class so he decided to audio record the review on his computer. He then transcribed this at home which was an excellent study technique. I can't even tell you how proud I am that he thought of this and solved his problem himself. It's like . . . progress.
