利用声栅原理揭秘多级阶梯奇特乐音现象
Using the Sound Grid Principle to Reveal the Phenomenon of Peculiar Multi-Step Music

光波经过光栅作用形成的光强分布，实际是光栅的单缝(槽)衍射和多缝(槽)干涉的共同结果。经观察发现，级数足够多的阶梯对一定强度的入射噪音反射后，在反射声场中将会获得某特定频段的乐音。本文仿照闪耀光栅将多级阶梯视为平面反射声栅即闪耀声栅，给出闪耀声栅声强分布，还给出相应的相邻槽间反射声波的路程差满足的约束关系。同时，根据实地考察的测量数据和相应的频谱曲线结合平面反射声栅原理对多级阶梯反射声场中形成的乐音现象予以分析，并以中国江苏茅山苏南抗战胜利纪念碑的“碑下放鞭炮空中响军号”和中国山东青岛鹤山的“招鹤回鸣”等两个现象作为实例予以阐释。
The light intensity distribution formed by light waves through gratings is actually the result of single slit (groove) diffraction and multi-slot (groove) interference of grating. It has been observed that after a step with enough stages reflects the incident noise of a certain intensity, the tone of a certain frequency band will be obtained in the reflected sound field. In this paper, the glare grating is regarded as a plane reflection sound grid, that is, the blazed sound grid, which gives the distribution of the sound intensity of the blazed sound grid, and also gives the constraint relationship that the corresponding path difference of the reflected sound waves between adjacent grooves is satisfied. At the same time, according to the field survey data and the corresponding spectral curve combined with the principle of plane reflection acoustic grating, the music phenomenon formed in the multistage step reflection sound field is analyzed, and the firecrackers under the monument of the Susan Anti-Japanese War Memorial in Maoshan, Jiangsu, China. The two phenomena of the “Put the firecrackers in the air under the monument” and “Recruiting crane” in Heshan, Qingdao, Shandong, China are explained as examples.