THE SENSE OF HEAKING 



231 



the character of the tone, i.e. its quality (Hermann, 1894 ; Lindig, 

 1902). Hence it may be concluded that our ear does not perceive 

 the form of the vibration as such, but that it is capable of per- 

 ceiving the partial tones that result from the analysis of the 

 compound tones. In other words, in so far as the ear is able to 

 distinguish the timbre of the different musical instruments, it is 

 capable of analysing tones and of detecting the partials of which 

 they are built up. 



X. The fact that the ear is capable of perceiving not only the 

 entire mass of sound, but also the separate elements of many 

 different tones and noises produced simultaneously, is yet more 

 astounding. A musical ear is able to follow the tones of the 

 several instruments of an orchestra. Each note of each instrument 

 forms its waves, which spread in all directions, cross, and are re- 

 flected from the surrounding 

 walls, partially extinguished 

 by interference, partially 

 summated and reinforced by 

 coincidence. This whirlpool 

 of waves intermingling in 

 every direction cannot be 

 discerned by the eye, but the 

 ear is quite capable of per- 

 ceiving it, both as a whole 

 and in its separate elements. 

 All these sound-elements are 

 already mingled when they 



reach and act Upon the FIG. 93. Combination of two sinusoidal waves, in 



drum of the ear, i.e. all the 

 component elements are com- 

 bined in their algebraic ordi- 

 nates into a very complex 

 vibration. In the same way they reach and act upon the 

 membrane of a phonograph, which inscribes with its needle on 

 the rotating disc the compound curves of vibrations in which are 

 collected all the tonal elements that have contributed to their 

 formation. 



These complex resultant vibrations are transmitted as such 

 from the tympanic apparatus to the organ of Corti, where a 

 marvellous analysis takes place which renders us capable of 

 feeling and distinguishing the tones of different instruments, 

 individual human voices, the mixture of tones and noises which 

 constitutes language, the rustling of clothes, the sound of steps in 

 a dance, and the voices of passers-by during the procession of 

 life in a great city. 



The best proof of the fact that the elements of a polyphonic 

 mass are not transmitted separately to the internal ear, but are 



which the ratio of amplitude is 2 : 1 (fundamental 

 and octave) ; in the upper figure there is no dis- 

 location of phase, in the lower there is a dislocation 

 of one-fourth the octave-wave. The two resulting 

 curves, drawn with a heavier line, are very different 

 in form. (After K. L. Schafer.) 



