An active control sound generator apparatus may include a housing disposed at an end of an intake duct in a vehicle, having an intake port at an end, and having a driving unit case thereon, a control actuator disposed at a side in the driving unit case, a valve plate disposed in the intake port and connected to a rotary shaft, wherein the valve plate selectively opens or closes the intake port, a control unit including a position sensing wheel disposed at an end of the rotary shaft of the valve plate, in the driving unit case to measure a rotation amount of the valve plate, and a driving gear assembly engaged with the valve plate and the rotary shaft, in the driving unit case, and reducing and transmitting torque of the control actuator to the rotary shaft.