Type this in your console

https://gist.github.com/wesbos/cd16b8b1815825f111a2

  speechSynthesis.onvoiceschanged = function() {
      var msg = new SpeechSynthesisUtterance();
      msg.voice = this.getVoices().filter(v => v.name == 'Cellos')[0];
      msg.text = Object.keys(window).join(' ');
      this.speak(msg);
    };