Prediction of scattering effects by sonic crystal noise barriers in 2-D and 3-D finite difference simulations

Sonic crystals have been investigated in recent years both as a potential form of noise barrier, and as a form of sonic art aimed at enhancing perception of the surrounding acoustic environment. The broader aim of this research is concerned with the auralization of these structures, which has, as yet, rarely been attempted. In a previous publication, prediction of the acoustic wave propagation through 2-D arrays of solid, cylindrical scatterers embedded in air was performed in 2-D Finite Difference Time Domain (FDTD) simulations. In this paper, the model has been extended into the third dimension and the results are compared with those obtained in the previous experiment. In both the 2-D and 3-D simulations the location of the fundamental band gap corresponds with the predicted location - predictions being based on simple theoretical considerations relating the frequency of the transmission gaps to the array configuration.