ENERGY DISTRlBVriOS IN Sl'EI-.CH 



123 



exhibit the mean square of the excess pressure on the diaphragm, as a 

 function of frequency in the voice exciting the vibration. We obtain 

 this corrected curve by dividing the results, after the first and second 

 corrections above have been made, by the ordiiiates of curve R. 



Observations 



In order to investigate the possibilities of this method it was decided 

 to work with a rather short piece of connected speech, and to use a 

 limited number of observers, on account of the large number of ob- 

 servations which are required for each separate syllable. With six 

 speakers (four men and two women) each pronouncing the test sentence 

 of fifty syllables for each of the twenty-three frequency settings, 6,900 

 separate observations were required. It is believed that representa- 

 tive results have been obtained from these observations, but if this 

 is not the case then some method of graphical registration of the energy- 

 time curve of speech for the different frequency settings must be 

 applied in order to handle the vast amount of data involved in work 

 on an appreciably larger scale. 



The test sentence used was as follows: 



"Quite four score and seven years ago our father brought forth on this continent, 

 a nice new nation, conceived in liberty, and dedicated to the proposition that all 

 men are created equal." 



TOGO Soo5 4oOO ^OOO 



Fig. 6 — Energy Distribution: Composite Curves of Male and Female Voices 



The two italicized words were added to the first sentence of the 

 "Gettysburg Address" in order to bring the total up to fifty syllables, 

 and improve the balance between the vowel sounds. 



The resulting speech-energy curves are shown in Figs. 5, 6 and 7, 



