Am I the only one who isn't getting any audio from the video at all? I tried in two different browsers, downloaded the video with youtube-dl and tried to play it with mpv, everything to no avail, it's just a video with no sound.
$ youtube-dl -f 18 http://newsoffice.mit.edu/2014/algorithm-recovers-speech-fro...
You can use the -F option to list the available formats.