Turn documents into lip-synced video readers

I read a lot of pdfs and papers, and I bounce between "read it myself" and "listen to it". So for quite some time wanted to experiment with adding a lip-sync video. I wanted something that keeps the original page in front, narrates it and show exactly where word-by-word with the lip-sync video reading it - Closer to a YouTube explainer than an audiobook. I’d be interested in feedback on the interaction model, the usefulness of lip-synced presenters for reading, and where this kind of tool would be most valuable: education, accessibility, research, documentation, or something else.