Students can HEAR it when they are interacting in teams. Students know how to spread the quiet signal to others. Room should be quiet within 3 to 5 seconds. If it takes longer, it's not working. Teacher holds up one hand and slowly counts to 3.
Students look at teacher, hold up one hand, and put finger to lips to signal others.
Room must be quiet by the count of 3. Teacher claps 2 times slowly. Teacher holds up rain stick and shakes it. Students hold up one hand to signal others. Room must be quiet by the time the stones in the rain stick fall to the bottom.