The result of rib stiffening is the redistribution of natural frequencies and mode shapes of the plate, which can significantly alter its noise and vibration character. In this paper, genetic algorithms are used as a promising tool for sound radiation minimization problems. The objective of the study is to determine effective, general design methods for determining the optimal dimensions of the stamped rib in a plate to minimize the total radiated acoustic power. Acoustic response under broad-band excitation is considered. Radiated sound power is calculated using a boundary element method, in conjunction with a finite element solver for the solution of the structural problem.