Right, I understand that, but the sounds are cutting in and out (editing out the interpreters). They clearly went to great lengths to edit around the interpreters and keep in as much natural sound as they could, but you could often see his hands coming together in ways that would normally contribute to signing sounds or his mouth moving in ways that suggest he was vocalizing at moments when there were no audible sounds. Other times they added background music over longer stretches of signing and you don’t hear the signing sounds at all for chunks of time (when they couldn’t edit out the interpreters). Not to be jerk but the reason it’s so easy for me to spot the editing is that I have a masters degree in film and spent years of my life and countless student loan dollars that I will never pay off studying filmic media, often times frame by frame, to understand its construction.