Railway applications - Track - Noise barriers and related devices acting on airborne sound propagation - Test method for determining the acoustic performance - Part 4: Intrinsic characteristics - In situ values of sound diffraction under direct sound field
铁路设施.轨道.作用于空气声传播的噪声屏障和相关装置.声学性能测定的试验方法.第4部分:固有特性.直接声场下声绕射的现场值