506 ANNUAL. REPORT SMITHSONIAN INSTITUTION, 1924 



interpretation. Failure to perceive them correctly is principally 

 due to their very weak energy although it is also to be noted that 

 they have important components of very high frequency. 



These data are of fundamental importance in the art of elec- 

 trical communication. But they have also a broader interest and 

 utility. The information gleaned by physicists in the study of 

 speech and hearing increases the understanding of phoneticians 

 and physiologists. It will aid public speakers, linguists, and phy- 

 sicians, and help to lighten the burdens of the deaf and dumb. 

 Investigators who engage in the field of human acoustics have 

 many interesting physical problems to solve. Furthermore, study 

 of these senses, dealing as it does with two of the primary tools 

 of the human race, is work of extraordinary appeal holding forth 

 promise of direct service to mankind. 



BIBLIOGRAPHY 



1. Analysis of the Energy Distribution in Speech. 



I. B. Crandall and D. MacKenzie — Phys. Rev. XIX, No. 3, p. 221, 



2. The Nature of Speech and its Interpretation. 



H. Fletcher— Jour. Franklin Inst., June, 1922, p. 729, 



3. The Frequency Sensitivity of Normal Ears. 



-H. Fletcher and R. L. Wegel— Phys. Rev. XIX, No. 6, p. 553. 



4. The Physical Examination of Hearing and Binaural Aids for the Deaf. 

 R. L. Wegel — Proc. Nat. Acad, of Sciences, Vol. 8, No. 7, p. 155. 



6. The Sensibility of the Ear to Small Differences of Intensity and Frequency, 

 V. ,0. Knudsen— Phys. Rev. XXI, No. 1, p. 84. 



6. Physical Measurements of Audition and their Bearing on the Theory of 



Hearing. 

 H. Fletcher — Jour. Franklin Inst., Aug., 1923, 



7. The Auditory Masking of One Pure Tone by Another and its Probable 



Relation to the Dynamics of the Inner Ear. 

 R. L. "Wegel and C. E. Lane — Presented to the American Physical Society, 

 April, 1923. (To be published in the Physical Review.) 



