In populated and urbanized areas, noise disturbance from cars increasingly becomes a problem. Whisstone by 4Silence reduces noise pollution from traffic by means of diffraction. Whisstone is a concrete panel embedded in the ground next to road. In this panel grooves of different depths absorb and redirect noise in upward direction. This creates a noise barrier that reduces pollution in areas adjacent to the road. Whisstone is easy to implement and takes up little space. It can be used in combination with other noise reducing techniques, or independently at locations where sound walls cannot be placed.