Aerodynamic noise is a major source of wayside noise generated by high-speed railway vehicles, and thus it is important to reduce this phenomenon. For this purpose, a new aerodynamic noise reduction method that involves covering the surface of objects with particular porous materials has been developed. To verify its aerodynamic noise reduction effects, wind tunnel tests using cylinders and high-speed pantographs were conducted. Field tests using the high-speed pantograph were also conducted. The results indicated that aerodynamic noise generated from the cylinders and the high-speed pantographs was reduced by the application of porous materials, thus confirming the effectiveness of this method. An advantage of this method is that it is possible to reduce aerodynamic noise with little modification of object shape. Furthermore, separate wind tunnel tests also demonstrated the effectiveness of the method in reducing aerodynamic noise in combination with simplifying the shape to allow easier material processing.