I don't get video/audio. What did the son of a bitch say?
"Hmmm","Ahhhh",and a few grunts. Seriously. Looks like somebody forgot to turn the teleprompter on,and evidently the book he brought to the podium with him was just for show and had nothing but blank paper in it.
Biden and others were all laughing,so somebody slammed a book closed and stood,and that was the sign Obomber used to say "Thank you" and move away.
He is quite literally,a dummy. Somebody has to pull the right strings and put the words in his mouth,or he has nothing to say.