Quickstone Boomstick
Rod, Uncommon (Requires Attunement)

Whenever you cast a spell of 1st-level or higher using this Rod as a Spellcasting Focus, you can choose to release its power in a thunderous burst. All creatures within 5 feet of you (including you) must make a Constitution saving throw against your spell save DC. On a failed save, affected creatures take 1d4 Thunder damage for each level of the spell you cast, and are Deafened until the end of their next turn.