My students with learning disabilities that affect their ability to read text are given audio devices and downloaded texts; they listen and follow along with their eyes and fingers. That way they can access grade level content that they can't read yet. Some of them may never be able to read those texts. They also have devices with text to speech and speech to text functions to use as needed. For these people, it's not cheating.
For my students who can read, I expect them to read. They aren't adults yet; they are still developing reading skills. A parent just asked me this a couple of days ago" "Can he use an audio book?" My answer: "Your son doesn't need it, so, no. We're still working on reading skills in 6th grade."
That said, there are certainly times audio books are useful, and not cheating. For informational text that requires multiple readings, an audio version while jogging or hiking or as a passenger in a car is useful. It reinforces the reading and annotating done with the text. Audio and visual text can support and reinforce each other in this context. A few decades ago, as a college student, I used to take careful notes of lectures, and then read my notes into a cassette recorder and play it in my car while driving. As long as I understood the content already, that hearing the information in my own voice repeatedly helped me prepare for exams. Sometimes, when a very dry passage in a text book left me "reading" pages while my brain wandered, I'd read into my recorder and play that back, as well.
Finally, our brains simply don't process information exactly the same way. For example, I'm a very visual person. If I see it, I'll remember it faster. If I hear it, I'll forget it, unless I've heard it over and over. Some people are the opposite; they remember what they hear better than what they see. Seeing AND hearing supports us all. (And, of course, there are other ways of processing information, as well.)
= new reply since forum marked as read