Detect when the page has been changed

I want to play an audio that reads the book whenever the page has been changed, but I am having a hard time figuring it out how to do that exactly.
How would I detect when a page has been changed?

Start with the repository's page-turn widget entry point and inspect how page transitions are exposed. Determine whether the widget reports a completed page change and document or implement a clear way for callers to react to it; done means an audio reader can reliably trigger after a page changes.

Written by the indexing model from the issue text.