Comment by tangledhelix

There are many books available as audio, some are human-read, some were automated. You can see lists here:

human-read: https://www.gutenberg.org/browse/categories/1

computer-generated: https://www.gutenberg.org/browse/categories/2

IIRC many of the human-generated ones come from LibriVox, many of the computer-generated ones came from a collaboration with Microsoft.