For the duration, no sound can be created within or pass through a 20-foot-radius sphere centered on a point you choose within range. Any creature or object entirely inside the sphere is immune to thunder damage, and creatures are deafened while entirely inside it. Casting a spell that includes a verbal component is impossible there.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the radius of the sphere increases by 10 feet for each slot level above 2nd.