82 



THE STUDY OF SPEECH CURVES. 



two harmonics than it does to a harmonic, and f of the highest ampUtude 

 are taken. The results are thus : 



The plot of components is given in figure 84. 



Harmonic analysis of a wave from the vowel [o] of "called" (figure 

 85) gives the results (figure 86) : 



Partial 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 



Amplitude". ........ .6.0 4.1 16.9 47.6 5.7 10.4 26.6 5.1 5.8 2.6 4.6 1.7 2.2 2.7 2.7 1.6 1.8 0.9 1.2 1.0 



Minima are found at the 2d, 5th, 8th, 10th, 12th, 16th, and 18th 

 harmonics; the values are divided as before. Except for the first and the 

 last components the calculation proceeds as in the previous case. For 

 the first component we must consider that there is no probabiUty that a 

 wave was present where the period was just a Uttle shorter than that of 

 the fundamental; on the contrary we have every reason to beUeve that 

 the fundamental was certainly present and we therefore assume it as the 

 first component. For the last component we can perhaps best use only the 

 last two numbers, obtaining 



(19x1.2) + (20x1.0)^^0 2 

 1.2+1.0 



For the amplitudes we take those of the strongest harmonic in each 

 group or f of it according to the rule just given. We thus obtain the 

 set of partials as follows: 



The plot of components is given in figure 87. 



A systematic accumulation of vowel analyses like these examples 

 may be expected to answer such questions as the following ones: What 

 is the nature of a vowel by which it is distinguished from the tones of 

 musical instruments? How is one typical vowel distinguished from 



