this is it right here, most think you can absorb an audio book while driving, driving in itself is a major task and needs focus, audio books are for walking or just sitting having a coffee where the main task is listening to the book, if you listen to an audio book while doing other tasks you will not absorb it all, kinda like you don't read and drive, its the same thing, you cannot visualize the book and focus on driving at the same time and do both well.

sitting and listening to an audio book is the same as reading it if done under the same conditions, most people like to combine it with other activities then say it didn't work.