一根长度一定两端开口的管子可以使噪音中的某一频率成份在管的空腔内共振,共振条件是波长为管长的两倍。截取八只长短各异的管子,就可以组成一个有八个音的“乐器”。把这八只管子排列好并固定在一起,放在楼厅中。当我们把耳朵从一个管口移到另一个管口时就会听到不同的乐音,这些乐音是从空气中由共振器挑选出来的。 A tube of a certain length at both ends opens a cavity in which a certain frequency component of the noise resonates at a wavelength that is twice the length of the tube. Intercept eight different lengths of pipe, you can form an eight-tone “instrument.” Arrange the eight tubes and fix them together in the hall. When we move our ears from one nozzle to another we hear different tones, picked from the air by the resonator.