This year the theme is shout silently. Shout silently means actions that speak. For example some people might be able to tell that that they can see God in you. I think the 8th graders were thinking when they picked this theme is that you can shout silently in a lot of different ways. Psalms 19:3-4 says:
3 They have no speech, they use no words;
no sound is heard from them.
4 Yet their voice goes out into all the earth,
their words to the ends of the world.
In the heavens God has pitched a tent for the sun.