I don't know if it was audible on the television, especially since you couldn't watch it at home, but when Robinson went down the Indiana student section cheered loudly.
I know Drew Stanton thinks this happened to him at Michigan when he went down in 2004 - I don't remember it this way. But with Robinson there is no denying it. Robinson was tackled - normal cheer. Then after a few seconds when it became apparent he was still down then the crowd went crazy. I've never seen anything like that. It is one thing to think to yourself "wow, that could help us"... it is quite another to cheer lustily about an injured opponent.