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BELL SYSTEM TECHNICAL JOURNAL 



the mean energy distribution for the four male speakers, using the 

 syllables, while Curve B is the mean energy distribution of the two 

 female speakers. Curves ^A and 95 may be compared with Curves 

 6-4 and 65 which represent the sentence of continuous speech. The 

 two sets of curves are essentially the same as shown in Fig. 8, C and B 



Fig. 9- 



-Energy Distribution in Disconnected Speech 



being respectively the composite curves for all speakers, using con- 

 nected and disconnected speech. 



Such small differences as exist between Curves C and B of Fig. 8 

 may probably be due to differences in the distribution of the vowel 

 sounds in the connected and disconnected test material. This dis- 

 tribution is given in the following table: 



Vowel Sounds 



In Sentence 



In Syllabic List (N: 

 174) 



Total 

 50 

 50 



Key to Vowel Sounds: a, as in father (or o as in top) i, as in time 



a, as in tape o, as in ton 



a, as in tap 6, as in tone 



e, as in ten 6, as in for 



e, as in team u, as in pull 



er, as in term u, as in rule 



i, as in tip ou, as in house 



The similarity between Curves C and B of Fig. 8 is evidence of the 

 general reliability of the method, and leads to two rather important 

 conclusions. 



In the first place, characteristic results have been obtained for a 

 given set of speakers, using two different types of test materials. This 



