Upon an attacker hitting you, you let out a tremendous wail. All the creatures within a 10 ft. sphere centered on you must make a constitution saving throw, or take 2d8 thunder damage and be stunned for 1 round on a failed save, or take half as much on a successful save and not be stunned.

At higher levels: Whenever you cast this spell at higher levels, it does 2d8 more thunder damage, and the radius of the sphere extends by 5 ft.