Initial results for traffic noise mitigation with Helmholtz resonators in the ground surface beside a road

For reduction of road traffic noise, measures focussing on the propagation path are needed as complements to measures at source. Here, the effect of Helmholtz resonators, buried in the ground surface alongside the road, is investigated. Possible benefits of buried resonators are that they can function without obstructing the accessibility to the protected area. A modelling approach using equivalent sources is described for a coupled field of resonators in an otherwise acoustically hard ground plane. The model is validated in comparison with laboratory measurements. For selected road traffic cases, the model is used to predict the effect of resonators in a grid pattern within a strip along the road, showing noise reductions of 2-4 dBA