孔板吸声
Sound absorption by orifice plate
微穿孔板其原理是在板上钻一定数量的孔，板后留有一定的空气层，使入射的声波产生共振吸收，从而达到吸声的效果。微穿孔板声屏障已被广泛应用于高速公路、城市高架等地方。微穿孔板材料从最早的PC板、亚克力板，发展到彩钢板、铝板等多种金属材料。
The principle of micro perforated plate is to drill a certain number of holes on the board, and there is a certain air layer behind the plate to make the incident sound wave produce resonance absorption, so as to achieve the effect of sound absorption. Micro perforated panel noise barrier has been widely used in highway, urban viaduct and other places. Micro perforated plate materials from the earliest PC board, acrylic plate, developed to color steel plate, aluminum plate and other metal materials.
微穿孔板的优点是：
The advantages of microperforated plate are as follows:
耐高温，耐潮湿，耐高速气流冲击。
Resistant to high temperature, humidity and high speed airflow impact.
具有稳定的吸声性能，平均吸声系数大于0.60，降噪系数NRC0.60左右，符合道路声屏障声学要求。
The average absorption coefficient is more than 0.60 and the noise reduction coefficient is about nrc0.60, which meets the acoustic requirements of road noise barrier.