The DefinitelyTyped definitions for this API have some differences that appear correct. SpeechSynthesisUtterance.onstart and other methods should have a SpeechSynthesisEvent as their event type, and not just Event. We already have a SpeechSynthesisEvent type defined in lib.dom.d.ts, but aren't using it everywhere we should.
The DefinitelyTyped definitions for this API have some differences that appear correct.
SpeechSynthesisUtterance.onstartand other methods should have aSpeechSynthesisEventas their event type, and not justEvent. We already have aSpeechSynthesisEventtype defined inlib.dom.d.ts, but aren't using it everywhere we should.