CHAPTER VIII. 



WAVE ANALYSIS IN REFERENCE TO VOCAL ACTION. 



An element of speech may be "physically" defined by the properties 

 of the vibrations transmitted through the air. It may be " physiologically" 

 defined by a description of the action of the vocal organs producing it, 

 or of the ear in receiving it. Or, finally, it may be "psychologically" 

 defined by a description of the hearer's or speaker's perception of the 

 sound as heard or spoken. 



A vowel analysis may be physical, physiological, or psychological. 

 The physical analysis may follow different methods; for example, it may be 

 an analysis of the vibration in the air by means of resonating instruments, 

 or an analysis of the record of vibration. The present researches are con- 

 cerned only with the analysis of the records of the physical vibration, 

 the data and references up to 1902 for the other forms of analysis are 

 given in my Elements of Experimental Phonetics. 



The complete analysis of a vowel curve includes a description of its 

 characteristics (Chapter III), the measurements and plots for its duration, 

 melody and intensity (Chapter IV), and the mathematical analysis of each 

 wave. This latter step requires special consideration. 



The physical analysis of a wave may take different forms. The wave 

 may be analyzed into (1) an arbitrary set of vibrations, (2) a set of vibra- 

 tions corresponding to the physiological action that produced it, (3) a set 

 of vibrations corresponding to the action in the ear, (4) a set of vibrations 

 corresponding to the elements of the sound heard. 



In the present chapter, I will attempt to show how the analysis of 

 a wave is to be made in order to correspond to the vocal action by which 

 it was produced ; the following chapter will discuss similar problems for the 

 physiological process in the ear and for the mental act of perception. 



The method to be selected in order to analyze a vowel into the ele- 

 ments out of which it was built up will depend on the nature of the action 

 of the vocal organs. The prevailing views have now to be discussed. 



The "overtone theory" arose from supposing the vowels to be pro- 

 duced like the tones of some musical instruments. When a musical string 

 is snapped, its vibration as a whole produces a strong tone, the "first 

 partial" (or "fundamental"). When it is snapped and then touched at the 

 middle, it continues to vibrate in halves, and the octave or "second partial " 



