The purpose of this study is about noise reduction by Active Noise Control (ANC) at the opening with a louver which attached Piezoelectric Card Speaker. In a house and an apartment not only machinery, louvers are used at large opening aimed for air conditioning and ventilation. Leakage of a sound from the opening set louver becomes a problem. In this experimental study, proposed ANC system is independent parallel control system using two single channel ANC systems. One of them, secondary noise source is set at each bane down side of louver. The other one is set slit of enclosure opening. The experimental results show that noise reduction is obtained from 5dB to 25dB in sound field on this proposed ANC system.
