All of them, but PAX Quiet is absolutely essential. Hand clapping, whistles, chimes, gongs, shouting, etc. are simply not as effective. Beat the Timer is essential for playing the Game and awarding the prizes. The use of the terms PAX and Spleems is essential. And PAX Voices works better than other voice cues, especially compared to “ssshhhhiing” and telling children to “be quiet.”