The slat noise of three-element 30P30N airfoil in high-lift configuration is computed by a LES/LPCE hybrid method with Brinkman penalization. The three-dimensional turbulent flow at Rec=1.7×106 and M=0.17 is computed by incompressible large eddy simulation (LES), while acoustic field is calculated by the linearized perturbed compressible equations (LPCE) coupled with Brinkman penalization. An anisotropic permeability tensor is introduced in the momentum equations to impose a slip boundary condition at the impermeable boundaries. The result of present method with body-fitted Cartesian-like grids is validated with that of the conformal multi-block structured grids. Besides, flow structures in the slat cove region are investigated in relation to the noise generation, and finally the effect of porous trailing-edge is examined for reduction of slat noise.