A noise reduction means for a wind turbine blade comprising an active noise reduction device and a passive noise reduction device, wherein the passive noise reduction device comprises at least one serrated edge profile adapted for fixation to a trailing edge of the wind turbine blade, wherein the active noise reduction device comprises at least one unsteady pressure sensor adapted to produce an output signal corresponding to a turbulent flow condition during operation of the wind turbine blade, at least one actuator and a control unit, wherein the sensor is arranged adjacent to a serrated edge of the serrated edge profile and the control unit is adapted to control the actuator in dependence of the output signal of the sensor to emit an anti-noise signal at least partly reducing a noise generated by the wind turbine blade.