kaall 2 points
Where are the audiobooks supposed to come from?
If the person is blind they probably have access to a library for the blind. The format that superseded the casette there is DAISY. It usually comes on a data CD and there are plenty of blind-user friendly playing devices, since its a format specifically designed for the blind. Such a player will be a tad more expensive than a casette player though.
It has many benefits over casette: you can easily skip around in the book, set bookmarks or other markers and almost any book fits on a single Disk. Such a player would also be able to handle regular CDs, which is what most commercial audio books come on these days.
To assess the situation with libraries for the blind and availability of daisy players it would help to know what country you are from.