Blind people have a hard time reading electronic books. If you are trying to equate audiobooks and e-books, you are being dishonest. For the record, my MIL is visually impaired and I am very familiar with the audiobooks on SD carts she orders for her player. Those are audio recordings, not e-books.
Without going through a great deal of discomfort trying to read one of the I-pads and I-pad like devices around the house (owned by my sons) I can watch a 22-24 inch screen and read anything.
I"m not blind yet but my visual limits are quite pronounced, and my reading these days is limited to my Mac! And as they make bigger and bigger screens I will get bigger and bigger Macs.
They've dumped everything on a 1T disk for me so as long as I have the read software on my Mac I can read it ~
Now about VOICE, there's software out there that turns any digital signal into sound ~ I have a couple of different versions on my Mac. I used them only a short time back when I was blind. Had trouble finding the keyboard though.
No doubt everything is not yet portable from platform to platform and system to system, but all that comes in due course. By the time i need my computer to talk at me it will do so with ease.