I know that speech synthesis has built in fuctionality for playing, pausing, and stopping an utterance. But how could I go about rewinding an utterance on a larger piece of text? For example, if a user would be listening to an utterance and there could be a play bar at the bottom that they can slide and it would rewind back to a point earlier on in the text by 30 seconds, etc? What way could I go about implementing this in JavaScript?