This is totally silly.
Absolutely.
And you will think that High School and Middle School students won't do it.
They will. And they'll love it.
Sometimes a lesson tanks. Or the class finishes an assignment a lot faster than you think it will. Or there are 10 extra minutes attached to a class that you didn't know about. Whatever.
This is when the beauty of Silent Ball comes into play.
This is not a game that teaches English. It teaches team work, keeps kids occupied, and can keep kids from trying to beat each other up in the classroom. Oh, and it can be modified to teach English. But this is not meant to be a full, regular school-year lesson. Think of it as a sponge to soak up that random 5 minutes here or there.
The idea of Silent Ball is that kids have to be silent. The teacher throws a ball to a student, which starts the timer. That student throws the ball to another, who then throws to another. Rinse, repeat. This goes on until the ball is dropped, someone gets too far out of their seat, or someone makes a noise of any kind. Then the timer starts over.
That's it. And it works. Eventually they learn how to keep the timer running. Once that happens, you can move into variations of the theme.
A good way to start is by having them say something that starts with the letters of the alphabet - actor, bank, candy - and then getting more specific - only food or only countries, that kind of stuff.
I recommend a beach ball or something like that, or else it might get ugly.