Did you try my code above? Because I had a draw(). Also, what browser and OS are you using?
From my limited testing, it works continuously most of the time. If you are referring to the code you posted, it only pops the last recognized word. In my code, I was printing all the words in the stack. If you stop speaking, I think it stops recognizing. If you start speaking, it activates again. Where you watching the console log messages? I did notice the sketch would get stack when restarting. I am guessing the system was trying to load the rec object and it hangs there. I suggest you do a broader search in the js community to see if this is observed in other projects or probly suggestions how to resolve your current issue. But first, become familiar with the library documentation.
Kf