Environmental noise reduction by sonic crystals barrier

In order to reduce unpleasant effects on human health in environment, recent research has moved towards low-frequency and broadband noise mitigation. However, traditional noise barriers have several common shortcomings: airflow blocking, inefficient noise reduction, visual obstruction. Inspired by the classic design of sonic crystals (SCs), the basic C-shaped unit is improved to replace the conventional vertical outdoor barriers with a compact size. This paper explores the acoustic performance of the shadowed-C-shaped SC both numerically and experimentally. The simulation results show that this novel design can achieve broader band gap in the range below 5000Hz, especially at the resonant frequencies, the transmission coefficients approach to zero. Experiments are carried out with a full-scale model to evaluate the practical application of SC as noise barriers. It is verified that there is a good performance of insertion loss in broadband which is basically consistent with the simulation results.