Possible Clues:

• Novel read by its author, maybe
• Recording of a written work
• Recording of a novel
• LibriVox download
• Spoken version of a novel
• Is this how people have heard of Ulysses and can't read it, no matter who says it?
• Some commuter 'reading'
• Novel recording
• 23 for one — in record form
• Novel that isn't read