CHAPTER XI. 



EXAMPLES OF VOWEL ANALYSIS. 



To illustrate the methods used in vowel analysis and give some idea 

 of their accuracy an artificial curve whose composition is known will first 

 be used. Thereafter an example will be taken from an actual vowel 

 curve. 



The vibrations in figure 121 represent one wave-group of a speech 

 curve, corresponding to the vibrations aroused by one puff from the glottis 

 (p. 40). We have first to find the axis of the curve. This is best done 

 while the vibrations are still in the continuous speech curve. It often 

 happens that successive wave-groups begin with vibrations of the same 



Tangential lino 



Fia. 121.— Curve for analysis. 



height. We draw a line along the tops of these highest vibrations and 

 get a " tangential line," as indicated in the figure. 



The distance of the maxima and minima of the vibrations from 

 this line are found to be 0, 168, 24, 162, 60, 153, 64. The vibrations start 

 strong and gradually die away. If the vibrations were of the nature 

 of those of a tuning-fork or a pendulum, the successive maxima and minima 

 would occur at equidistant intervals. In such a case the position of the 

 axis can be found by taking the average of the maxima and that of the 

 minima and averaging the two results. 



Although we have no proof that this curve is of the same character 

 as the pendulum curv^e with a vibration d>nng away, we can use the method 



^ 137 



