Page:Elementary Text-book of Physics (Anthony, 1897).djvu/193

§ 153] of hollow spheres or cylinders, called resonators, which are tuned to certain tones. If a tube lead from the resonator to the ear and a sound be produced, one of the components of which is the tone to which the resonator is tuned, the mass of air in it will be set in vibration, and that tone will be clearly heard; or, if the resonator be connected by a rubber tube to a manometric capsule (§ 128), the gas flame connected with the capsule will be disturbed whenever the tone to which the resonator is tuned is produced in the vicinity, either by itself or as a component of a complex tone. By trying the resonators of a series, one after another, the several components of a complex tone may be detected and its composition demonstrated.

153. Vowel Sounds.—Helmholtz has shown that the differences between the vowel sounds are only differences of quality. That the vowel sounds correspond to distinct forms of vibration is well shown by means of the manometric flame. By connecting a mouthpiece