Since 2009, I've been working with Authors. The problem is that it's not until they are fairly deep into the publishing process that they realize they want to change the structure of their book or fix typos. If they had listened to their own book being read aloud (and had others listen as well), they'd be able to produce a better product from the start.
Proofing different mediums: Our brains only see so much on the screen (level 1) (we miss many typos). A level 2 edit occurs when we see words in print - we often find additional typos we couldn't see on the screen. Level 3 is when we can listen to it and we hear things we couldn't see.
Over the years, Amazon Polly (AWS) TTS (Text to Speech) has dramatically improved. But the process I've been using to convert a manuscript to speech is labor intensive. Given there's an API to speed up the process, I want to see if we can build a solution where I could either upload a word doc or provide a URL instead of manually pasting each chapter into the Polly tool (I can show a demo).