The material below is Open Game Content from a 3PP Source
Chime of Interruption
Aura moderate evocation; CL 7th
Slot none; Price 16,800 gp; Weight 1 lb.
This instrument can be struck once every 10 minutes, and its resonant tone lasts for 3 full minutes.
While the chime is resonating, no spell requiring a verbal component can be cast within a 30-foot radius of it unless the caster can make a concentration check (DC 15 + the spell's level).
Requirements Craft Wondrous Item, shout; Cost 8,400 gp