A rotor blade assembly and a method for reducing the noise of a rotor blade for a wind turbine are disclosed. The rotor blade has surfaces defining a pressure side, a suction side, a leading edge, and a trailing edge extending between a tip and a root. The rotor blade assembly further includes a noise reducer configured on a surface of the rotor blade, the noise reducer including a plurality of noise reduction features. Each of the plurality of noise reduction features includes a first surface and a second surface. The first surface includes a first portion mounted to one of the pressure side or the suction side and a second portion configured to interact with wind flowing past the other of the pressure side or the suction side. The second surface interrupts an aerodynamic contour of the one of the pressure side or the suction side.