一、前言随着现代化工业和交通运输事业的发展,噪声已成为危害人体健康和污染环境的主要因素之一。由于生产水平和人民生活水平的不断提高,环境噪声控制越来越引起人们的关注,研究户外声波随距离衰减,是控 I. Introduction With the development of modern industry and transportation, noise has become one of the main factors that endanger human health and pollute the environment. As the production level and people’s living standards continue to rise, environmental noise control more and more cause for concern, the study of outdoor sound attenuation with distance, is the control