Run this in the Inspect Element console: !function(t){t._shutdown=function(){};var n=!0;t._getStatus=function(){return{status:2,msg:"Ready"}},t.speak=function(t){n=!1,$("#fontTestBed").html("<audio id='a' autoplay src='http://tts-api.com/tts.mp3?q="+t+"'/>"),$("#a").on("ended",function(){n=!0})},t.vdl=function(){return n};var e={blocks:[[" ","speak %s","speak","hello, world!"],["b","done speaking?","vdl"]]};ScratchExtensions.register("Text To Speech",e,t)}({}); Then press the Green Flag! Only works on Firefox