Bubbleblast

As you hold your hands with thumbs and index fingers touching and blow through the opening, a beam of sparkling bubbles streaks foward in a cone. The bubbles pop on impact, unleashing a chain of thunderous sounds that can be heard up to 100 feet away. Each creature in a 15-foot cone must make a Constitution saving throw. On a failed save, a creature takes 1d4 thunder damage and is knocked prone.

This spell's damage increases by 1d4 when you reach 5th level (2d4), 11th level (3d4), and 17th level (4d4).