Combined acoustical and economical noise barrier optimization using genetic algorithms This paper studies noise barrier optimization using the Boundary Element Method (BEM) as a numerical technique and Genetic Algorithms (GA). Noise barriers are optimised according to acoustical, technological and economical properties so as to obtain an optimum noise barrier. In order to optimise acoustical and economical properties of noise barriers, the use is made of a genetic algorithm that forms a noise barrier out of given shapes. A new noise barrier evaluation parameter, named the noise barrier cost parameter (K e), is also defined in the paper. Using the genetic algorithm and the noise barrier cost parameter (K e), it is easy to create, develop and construct an appropriate noise barrier.