声音,对于我们每个人来说都是很熟悉的一种物理现象,它可以向人们提供各种各样的信息。假如世界上没有了声音,人们将无法交谈,无法欣赏动听的音乐,人们也就失去了欢乐,包围人们的这个世界将毫无生气,一片死寂,因此很难想象人们将如何生活和工作。随着现代工业的发展,机器功率的容量越来越大,转速越来越高,各种设备所发出的噪声也越来越强;随着人类生活水平的提高,家用电器 Sound, a physical phenomenon that is familiar to all of us, provides a wide range of information to people. If there is no sound in the world, people will not be able to talk and can not enjoy the pleasant music, and people will lose their joy. The world surrounding the people will be lifeless and dead so it is hard to imagine how people will live and work. With the development of modern industry, the capacity of the machine is more and more large, the speed is getting higher and higher, the noise emitted by various equipment is also getting stronger and stronger. With the improvement of human living standards,