ABSTRACTS OF TECHNICAL ARTICLES 337 



quaver, or a single voice may accompany itself at any desired musical 

 interval— thus converting a solo into a duet, etc. Also non-speech 

 sounds may be coded into intelligible speech and instrumental music 

 into vocal music. 



Statistical Measurements on Conversational Speech.^ H. K. Dunn 

 and S. D. White. Using apparatus designed to collect a large number 

 of data in a short time, the following measurements have been made: 

 peak and r.m.s. pressures in one-eighth-second intervals, and in various 

 bands of frequencies up to 12,000 cycles per second, from the voices 

 of six men and five women; comparison of r.m.s. pressures in one- 

 eighth- and one-fourth-second intervals, from a single male voice; 

 and distribution of the instantaneous pressures in whole speech, from a 

 single voice. Derived from these data are peak factors in one-eighth- 

 second intervals, and frequency distribution of speech energy in long 

 intervals. Both the absolute value and the distribution of energy are 

 found somewhat different from previously published results. 



Auditory Patterns} Harvey Fletcher. During the last two 

 decades considerable progress has been made in understanding the 

 hearing processes taking place when we sense a sound. The applica- 

 tion of the same instrumentalities that have brought such a wonderful 

 development in the radio and sound pictures to this problem is largely 

 responsible for this progress. Such instrumentalities have made it 

 possible to make accurate measurements which are the basis for under- 

 standing any physical process. 



To understand this problem then we need to know first how to 

 describe and measure the sound reaching the ears; then we need to 

 know how to describe and measure the sensations of hearing produced 

 by such a sound upon a listener. To do this quantitatively we must 

 also know the degree and kind of hearing ability possessed by the 

 listener. It is with these three phases of the problem that this paper 

 deals. 



2 Jour. Acous. Soc. of America, January 1940. 

 *■ Reviews of Modern Physics, January 1940. 



