Do any of the commonly used screen readers emit browser events that can be scripted with javascript?
Or, are there current or planned javascript APIs to communicate with screen readers in the same way there are now APIs for working with other OS level systems (cameras, GPS, etc.)?
A similar question from three years ago (Evaluating current state of a screen reader in JavaScript) produced a definitive "NO" answer. Has anything changed since then?
I believe, it's still a No, but the closest to your request is the (drafted) Accessibility Object Model. It does not allow to interact with screen readers directly (it seems), but it does allow to manipulate the accessibility tree in a browser.
Currently supported at least in Chrome Canary via a command-line flag.