Thunderous Roar

Your voice becomes loud as thunder and sends all that hear it flying backwards with a loud roar that spreads in a 15 ft. cone. Any creature in that area must make a Dexterity saving throw, taking 6d8 thunder damage and getting knocked back 10 ft. on a failed save,  and half damage on a successful save.

At Higher Levels. When you cast this spell at 5th level or higher, the damage increases by 1d8 for each spell slot above 5th.