370 BELL SYSTEM TECHNICAL JOURNAL 



the weakest sound carry only about l/20th of a microwatt. Even for 

 an extremely loud shout or for the most intense singing the maximum 

 power will not exceed more than about 100 times these values; that is, 

 they will not exceed 1 watt. The pitch range necessary for faithfully 

 transmitting men's and women's speech is from — 3.5 to + ?>.Z 

 octaves or from 90 to 10,000 cycles per second. 



Acoustical Power Produced by Musical Instruments 



Now we will look briefly at some of the same results obtained for 

 music by the use of some of these same measuring tools. In Fig. 19 



^^S^^';Vw'V^^',^'s^ LOW E (dz) 147 CYCLES 



)A'^^W\v<,'w^-V''XV','w^a.',\ low G (fa) 175 CYCLES 

 ■*Vw^'V^Vw^'V^*Vv,"^^^W''*^\v LOW CCbz) 233 CYCLES 



Vv^;^S^;'>V^/^Vv\;\Vv^;'> THROAT E (da) 294 CYCLES 



'.»At, -,Ai, <fi'u ','i''. .,<•. ' 



uyM^:;J>:J'^::J^^'yy;^^' throat g (fj) 349 cycles 



'^>)>)>^'y'>)>}>}>^ MEDIUM C (b^) 466 CYCLES 



^':j":X!J''J!''J!'j}'J^^^^^^ medium E (d^) 587 CYCLES 



V'V^V'VVV,V)VV.V,V,V.V) MEDIUM G (f4) 698 CYCLES 



it' 



;ji M >t «\ n n,n >( i\ i{ ii »\ n M M M I 



^ .' HIGH C Cb^) 932 CYCLES 



Fig. 19 — ^Major triads of B-flat clarinet. 



are shown typical waves produced by the clarinet. A complete 

 oscillogram of the waves produced when the instrument played its 

 full range of three octaves on the chromatic scale was taken. The 

 simple waves shown in the figure are those corresponding to the major 

 triad in each of these octaves. The entire record was about 250 feet 

 long. Such musical tones have a much more uniform wave form than 

 those from the voice. 



