Abstract: The farfield noise of two dimensional multi-element high lift device L1T2 slat model was calculated using commercial CFD software FLUENT. LES model was used in flow field analysis to provide noise source data, while the FW-H method was used to calculate the far-field noise levels. To study the effects of gap and overlap on both maximum lift coefficient and noise levels, a total of 24 different combinations of gap and overlap were analyzed, and two response surface models were built from the results. The response surface models indicate that it is possible to find reasonable combinations of gap and overlap to achieve a balance between aerodynamic performance and noise characteristics.