The Theory of Hearing

Abstract

DR. HARTRIDGE'S interesting report (NATURE, May 17, p. 713) of experiments with light pendulums driven by resonance from a heavy pendulum of variable length, states that a careful change in length without interruption of motion resulted in a gradual dying out of non-resonant small pendulums with increased motion of resonant pendulums. The change must be gradual, not interrupted, and carefully made. A sudden change or a single brief impulse would result in irregular jangling. If Dr. Hartridge will hang his small resonance pendulums on a body that gives sudden jerks, he will find that each jerk will produce a jangle. The speech tone from the larynx does not consist of a sequence of pendulum vibrations but of a series of sudden jerks. These jerks do not come at a constant interval in speech but at an ever-changing one. Each jerk would produce in a pendular resonance system a jangle of tones, and the series of jerks would produce only continued jangle. This fundamental fact disposes not only of the harmonic theory of the vowels but also of the resonance theory of hearing.