D&Dtools

You empower the touched weapon with magic that causes it to emit a loud clang when it is struck against a hard surface, such as a floor, wall, or creature.
The item can create this noise once per round.
The clang has the effect of a thunderstone (see page 114 of the Player's Handbook) except that the caster and the weapon user are unaffected by the sound and the deafness lasts 1 minute.
If an attack with the weapon misses the target but was enough to make a touch attack, the weapon strikes the creature with sufficient force to activate the deafening clang.