588 BELL SYSTEM TECHNICAL JOURNAL 



imnicasiirahly sui)erior physical apparatus, and with more specialized 

 theoretical equipment, the individual investigator usually approaches 

 one problem at a time, the problem and the method being selected 

 according to the technique with which he is familiar. The work of 

 D. C. Miller on sound and sound analysis' represents the beginning 

 of modern physical research on speech sounds. In medical science 

 some attention has V)een given to the mechanism of speech ■* and the 

 psychologists are responsible for an enormous literature on voice 

 control and the perception of speech and tones. ^ The work of Scrip- 

 ture * represents the beginning of a science of experimental phonetics, 

 and in the closely related field of philology there is a rapidh" growing 

 interest in the physical characteristics of speech sounds.' 



In this large field of investigation the physicist finds a real oppor- 

 tunity in providing means for the stud\' and measurement of speech 

 sounds, and a real responsibility in broadening the extent and im- 

 proving the accuracy of such quantitative data as are obtained. 



The results obtained from such physical investigations have prac- 

 tical as well as scientific \alue, and we observe that in a large labora- 

 tory concerned entirely with the development of electrical com- 

 munication considerable effort has been devoted to research on speech 

 and acoustic apparatus.' It has recently been felt that the wave 



' "The Science of Musical Sounds," New York, 1916. This contains a bibliography 

 of 90 special references, some 12 of which relate specifically to speech. 



' " \ Contribution to the Mechanism of .Articulate .Speech," by S. W. Carruthers- 

 i;<lin. .Med. Jour. \111 (New Series) (190()i pp. 236, HI, 426. 



'"The I'sycholojry of .Sound," by Henry J. Watt (Cambridge, England, 1917), 

 contains a bibliography of 159 references. The work of C. E. Seashore is note- 

 worthy in this field. 



•"Researches in Experimental Phonetics." Publication No. 44, Carnegie In- 

 stitution, Washington, 1906. 



'"The Physical Characteristics of Speech Sound," by Marie H. I.iddell. Bulletin 

 .No. 16, Purdue I'niversity Engineering Experiment Station. 



• Sec follov\ing papers, from the Research Laboratories of the .American Telephone 

 and Telegraph Co. and Western Electric Co., Inc.: 



(a) H. D. Arnold and I. B. Crandall; The Thermophone as a Precision Source 

 of Sound: Phys. Rev. 10, (1917), p. 22. 



(b) E. C. Wenle: Condenser Transmitter for Measurement of Sound Intensity: 

 Phys. Rev. 10 (1917), p. 39. 



(c) I. B. Crandall: The Air Damped \ibrating System: Phvs. Rev. 11 (1918), 

 p. 449. 



(d) I. B. Crandall: The Composition of Speech: Phvs. Rev. 10 (1917), p. 74. 

 (e^ R. L. Wegel: Theory of Telephone Receivers: J. .\. I. E. E. 40 (1921). 



(f) E. C. Wente: .Sensitivity and Precision of the Electrostatic Transmitter: 

 Phys. Rev. 19(1922), p. 498. 



(g) I. B. Crandall and D. Mackenzie: Analysis of the Energy Distribution in 

 S|)eech: Phys. Rev. 19 (1922), p. 221. 



(h) II. Eletcher: The .Nature of Speech and its Interpretation: J. Franklin Inst. 



193 (1922), p. 729. 

 (i) J. y. .Stewart: .An Electrical Analogue of the Vocal Organs: Nature, Sept. 2, 



1922. 



