Interior noise control with an active window system

An active window system to reduce the exterior noise sources, such as traffic noise and construction noise which enter rooms through open windows used for natural ventilation is proposed. The proposed system uses a feedforward control method for active noise control so as not to place the sensors and control sources inside the interior space of the building. For global noise reduction throughout the interior room, the control gains for feedforward control are calculated to minimize the total acoustic power of the new source, which is combined with the noise source corresponding to the open window and control sources on the window frame. The performance of the proposed system for directional exterior noise is confirmed with a scale-model experiment. The experimental results show that the proposed system can achieve a noise reduction of up to 10 dB for the entire room of the scale model regardless of the direction of the incident wave.