CHAPTER XXX 

 SOUND 



201. Personal Experiences. We have not been in this 

 world very long before we have been attracted by a sensa- 

 tion received through the ears and have also attracted 

 the attention of those about us by our voices. We grow 

 able to produce sounds which are loud or soft according 

 to our wish. When we gain the ability to carry a tune, 

 we are able not only to distinguish one tone from another 

 as having a different pitch, but also to produce tones of 

 a different pitch. We then soon learn to note the 

 difference in the character of a tone produced by a piano 

 and a violin, a violin and a guitar, or a piano and 

 the human voice. We discover the echo as we walk 

 heavily in a large hall or speak loudly when at the proper 

 distance from a large building or steep hillside. 



During early youth we discover that the shrill whistle 

 of a locomotive or other steam engine is produced by the 

 emission of steam, and if we are at some distance from 

 the locomotive we see the steam a few seconds before 

 we hear the whistle; so we conclude that it requires time 

 for sound to travel over the space between us and the 

 locomotive. The time arrives when we no longer have 

 any difficulty in distinguishing between a noise and a 

 musical sound; and when several tones of different pitch 

 are sounded together, we soon decide whether the effect 

 is harmonious and pleasant or whether it is a discord. 



The foregoing are some of the experiences that we pass 



