Wall of noise
The wall of noise is a game that is devilishly loud. It is perfect when a group needs to should and talk a lot to (hopefully) be quieter during the following activities.
You don't need any equipment for that game.
The players are split into two groups. They are standing next to each other, a few meters/yards apart. One group is selected to transport a message; one player of this group moves to the other side of the other group (so the other group is standing between him and his own group).
The trainers then tell this player a word (or a short message). He has to submit that word or message to the other players of his team. He may not move to them, but has to stay where he is (as all other players have to); using pantomime or writing the word is prohibited as well. So, he could just "say" the word. The other group is trying to prevent the - by shouting very loudly. This can make it very hard for the group to recognize the word. How long does it take for the team to understand the message correctly?