可以根据降噪对象的高度确定。当降噪对象的高度小于声屏障的高度时，降噪效果最好。例如，隔音屏障在国外乡村的降噪效果很好。如果降噪物体的高度高于音障的高度，则相反。例如：高架桥的高层建筑中心，音障不足以降低噪音。在这种情况下，可以安装自然通风降噪口来降低噪音。
It can be determined according to the height of noise reduction object. When the height of noise reduction object is less than the height of sound barrier, the effect of noise reduction is the best. For example, the noise reduction effect of noise barrier in foreign villages is very good. If the height of the noise reduction object is higher than the height of the sound barrier, the opposite is true. For example, in the center of high-rise buildings of viaduct, the sound barrier is not enough to reduce the noise. In this case, natural ventilation and noise reduction port can be installed to reduce noise.