262 POPULAR SCIENCE MONTHLY. 



VOICE, SONG AND SPEECH. 



BY WM. SCHEPPEGRELL, A.M., M.D., 



NEW ORLEANS, LA. 



n[^HERE is no physical faculty which so distinguishes man from 

 -*- the lower animals, and marks him more conspicuously in the 

 image of his Maker than the power of articulate speech. That there 

 is some means of coramunication among the lower animals, we can 

 not doubt, but that faculty of articulate speech which enables us to 

 communicate to our fellowmen not only our ordinary desires and 

 wishes, but even the most delicate shades of our inmost thought, that 

 faculty belongs distinctively to the human race. 



This subject may be treated from various standpoints, but we will 

 here limit ourselves to a strictly physical consideration, explaining 

 first the general anatomy of the parts essential in the production of 

 the voice, and afterwards the manner in which these are used in the 

 formation of song and speech. 



Before discussing the subject of the voice, we must have some con- 

 ception of sound in order to understand more fully how the voice is 

 produced and how it is modified by the various parts concerned in the 

 faculty of speech. All sounds are due to the vibration of the sur- 

 rounding air, which conveys to the ear the vibrations produced by the 

 sound-producing object. Perhaps one of the simplest methods of pro- 

 ducing sound is by means of the tuning fork. When this is struck 

 the prongs are made to vibrate, and these in turn set up in the air 

 vibrations which are carried to the drum of the ear, and thence trans- 

 mitted to the brain as sound. 



In sound we have three important qualities, pitch, loudness and 

 timbre. The pitch depends upon the number of vibrations which the 

 sounding body makes in a given time. When these vibrations are 

 repeated less than eighteen times per second they produce no musical 

 tone to the ear. When a boy strikes a stick against a paling fence we 

 have simply a rattle. If, however, this could be done so rapidly as 

 to make more than eighteen beats to the second, then the ear would 

 cease to recognize each individual stroke and would perceive a musical 

 tone. The more rapid the vibrations the higher the tone, until the 

 limit of human hearing is reached, which is about 48,000 vibrations 

 to the second. 



The second quality of sound, which we may call 'loudness,' is due 

 to the range of the vibrations made by the sound-producing body. If 



