var T2S; 

if("speechSynthesis" in window || speechSynthesis){ // Checking If speechSynthesis Is Supported.

    var text = prompt("What Text To Say?") || `Text To Speech is Over Powered`; // Ask What To Say or use Default

    T2S = window.speechSynthesis || speechSynthesis; // Storing speechSynthesis API as variable - T2S
    var utter = new SpeechSynthesisUtterance(text); // To Make The Utterance
    T2S.speak(utter); // To Speak The Utterance

    window.onbeforeunload = function(){
        T2S.cancel(); // To Stop Speaking If the Page Is Closed.
    }

}