These bracers once belonged to a knight who fell out of favor with his king and fled his wrath out into the wilderness, where humans peacefully coexisted with the fey.
Time and again he raised his weapons when bandits or monsters threatened the lives of the locals. To help him, the fey enchanted his bracers with a powerful spell. After the knight eventually died, the bracers were stored as a relic in a local shrine of Erastil.
Many years later, trouble came to the village. For reasons unknown, one of the fey had lost her mind, turning into a monster and wreaking havoc around the village. People fled, terrified — all but one calm young acolyte in the shrine. He prepared for battle, arming himself with a pitchfork and girding himself with whatever he could find — an oven shutter for a chest plate, a saucepan for a helmet, and a pair of bracers he found in the shrine to protect his hands. He didn't expect to win — he just wanted to buy enough time for the villagers to run for safety. But still, he emerged victorious.
When the monster saw the bracers, she froze on the spot, moaning as if in pain. Her moan reverberated in the bracers — they trembled, droned, almost as if crying, then shattered. The monster remained frozen in that spot for three more weeks, then withdrew back to the forest. Alas, by that time the village was just a pile of rubble, but the majority of the people who lived there had survived — the bracers had aided a young brave soul in accomplishing their last heroic deed... until someone else found all the pieces and managed to restore the bracers once more.
Being immune to Confused or Frightened does not prevent you from getting Hideous Laughter effect.