Chapter 7: The value of humility (paragraph 17)
The tenth step of humility teaches us that we should not be given to empty laughter on eatery least occasion because: a fool's voice is forever raised in laughter. (From para. 17 of Ch. 7 of Saint Benedict's Rule, trans. by Patrick Barry, OSB, 1997.)
I think that empty laughter has a loud and hollow sound, and points to the isolated ego. Laughter that is full of joy leaps from heart to heart, and creates community.