Definition
Web Speech API defines SpeechSynthesisUtterance
[Exposed=Window]
interface SpeechSynthesisUtterance : EventTarget {
constructor(optional DOMString text);
attribute DOMString text;
attribute DOMString lang;
attribute SpeechSynthesisVoice? voice;
attribute float volume;
attribute float rate;
attribute float pitch;
attribute EventHandler onstart;
attribute EventHandler onend;
attribute EventHandler onerror;
attribute EventHandler onpause;
attribute EventHandler onresume;
attribute EventHandler onmark;
attribute EventHandler onboundary;
};