Assassin's Friend

With a series of quick arcane passes, you throw out an invisible sphere of silence around you in a 10 foot radius. Sounds created inside the sphere do not travel beyond its boundary, though sounds from outside can still come in. The sphere travels with you, centered on you.

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 per slot level over 2nd.