Road and railway authorities face a large and growing challenge. Today, more than 1 in 4 Europeans is exposed to traffic noise levels dangerous to their health in their homes, schools and workplaces. The World Health Organization has classified traffic noise as the second worst environmental stressor affecting human health in Europe, behind only air pollution caused by very fine particulate matter. 4Silence helps to solve the problem. Since its inception in 2012, 4Silence has dedicated itself to fighting traffic noise exposure. We have invented a highly innovative, but simple and sustainable solution based on the principle of diffraction, i.e. bending traffic noise in an upward direction in order to obtain horizontal noise reduction. This acoustic principle has never been translated into effective noise abatement solution before. It constitutes a revolutionary approach in the world of noise reduction, which traditionally focuses at noise absorption or blocking noise.