Abstract
An acoustic transparent wall was developed and applied to car air conditioner ducts for the purpose of noise reduction in a car cabin. The acoustic transparent wall is a plate through which sound can pass easily but flow cannot pass. This technique has already been applied to casings and ducts of ventilating fans to reduce the inlet and/or exhaust noise. In this paper, acoustic analysis was performed by use of the boundary element method. This analysis gives the sum of the acoustic impedance considered material characteristic and the radiation impedance considered shape to the boundary condition of the acoustic transparent wall. The simulation results of acoustic analysis were verified by compared with the measured results.The simulation results agree with the measured results.