216 



AUDITORY SIGNALS 



too great. One of the chief advantages of 

 the auditory signal is that the transmission 

 of information can be completely automatic. 



The radio range is a relatively simple form 

 of auditory signal, and research on the use 

 of the radio range involves simple intensity 

 discrimination of tones. Flybar, on the 

 other hand, is a complex form of auditory 

 signal which provides three simultaneous sig- 

 nals for use by aircraft pilots in flight. 

 These two systems of auditory signals have 

 been used to illustrate the type of research 

 which is done on these problems. 



The major research requirement for audi- 

 tory signals is basic research in the psychol- 

 ogy of hearing. Of the many topics which 

 are covered in that area, however, research 

 on simple and complex discrimination, stim- 

 ulus interactions, auditory localization, psy- 

 chological scaling, and auditory illusions ap- 

 pears to be the most profitable from the 

 point of view of possible application to the 

 problems of auditory signalling. 



References 



1. DeFlorez,L. True blind flight. J. aeronaut. 



Sci., 1936, 3, 168-170. 



2. Doughty, J. M. & Garner, W. R. Pitch 



characteristics of short tones. I. Two kinds 

 of pitch threshold. /. exp. Psychol., 1947, 

 37, 351-365. 



3. Doughty, J. M. & Garner, W. R. Pitch 



characteristics of short tones. II. Pitch 

 as a function of tonal duration. /. exp. 

 Psychol., 1948, 38, 478-494. 



4. Fletcher, H. & Munson. W. A. Loudness, 



its definition, measurement and calculation. 

 /. acoust. Soc. Amer., 1933, 5, 82-108. 



5. Flynn, J. P., GoFFARD, S. J., Truscott, I. p., 



& Forbes, T. W. Auditory factors in the 

 discrimination of radio range signals. Re- 

 port from the Psycho-Acoustic Laboratory, 

 Harvard Univ., 31 December 1945. OSRD 

 Report No. 6292. (Available through Pub- 

 lication Board, U. S. Department of Com- 

 merce, Washington, D. C.) 



6. Forbes, T. W. Auditory signals for instru- 



ment flying. /. aeronaut. Sci., 1946, 13, 

 255-258. 



7. Forbes, T. W., Garner, W. R., & Howard, 



J. G. Flying by auditory reference ("Fly- 

 bar"). Report from the Psycho-Acoustic 

 Laboratory, Harvard Univ., 1 June 1945. 



OSRD Report No. 5123. (Available through 

 Publication Board, U. S. Department of 

 Commerce, Washington, D. C.) 



8. Ford, A. Dynamic auditory localization. 1. 



The binaural intensity disparity limen. /. 

 acoust. Soc. Amer., 1942, 13, 367-372. 



9. Garner, W. R. Accuracy of binaural loud- 



ness matching with repeated short tones. 

 J. exp. Psychol., 1947, 37, 337-350. 



10. Garner, W. R. Auditory thresholds of short 



tones as a function of repetition rates. 

 /. acoicst. Soc. Amer., 1947, 19, 600-608. 



11. Garner, W. R. The effect of frequency spec- 



trum on temporal integration of energy in 

 the ear. J. acoust. Soc. Amer., 1947, 19, 

 808-815. 



12. Garner, W. R. The loudness of repeated 



short tones. /. acoust. Soc. Amer., 1948, 

 20, 513-527. 



13. Garner, W. R. Loudness and monaural loud- 



ness matching of short tones. (In prepara- 

 tion) 



14. Garner, W. R. & Miller, G. A. Differential 



sensitivity to intensity as a function of the 

 duration of the comparison tones. /. exp. 

 Psychol, 1944, 34, 450-463. 



15. Garner, W. R. & Miller, G. A. The masked 



threshold of pure tones as a function of 

 duration. /. exp. Psychol, 1947, 37, 293-303. 



16. Harris, J. D. Studies on pitch discrimina- 



tion in masking. II. The effect of sig- 

 nal/noise differential. J. acoust. Soc. Amer., 

 1947, 19, 816-819. 



17. HiRSH, I. J. The influence of interaural phase 



on interaural summation and inhibition. 

 /. acoust. Soc. Amer., 1948, 20, 536-544. 



18. Hughes, J. W. Binaural localization with 



two notes differing in phase by 180°. Brit. 

 J. Psychol, 1939, 30, 52-56. 



19. Hughes, J. W. The upper frequency limit 



for the binaural localization of a pure tone 

 by phase difference. Proc. roy. Soc, 1940, 

 B128, 293-305. 



20. Hughes, J. W. The threshold of audition 



for short periods of stimulation. Proc. roy. 

 Soc, 1946, B133, 486^90. 



21. Karlin, J. E. Auditory tests for the ability to 



discriminate the pitch and loudness of noises. 

 Report from the Psycho-Acoustic Labora- 

 tory, Harvard Univ., 1 August 1945. OSRD 

 Report No. 5294. (Available through Pub- 

 lication Board, U. S. Department of Com- 

 merce, Washington, D. C. ) 



22. Langmuir, I., ScHAEFER, V. J., Ferguson, 



C. v., & Hennelly, E. F. a study of 

 binaural perception of the direction of a sound 

 source. General Electric Research Labora- 

 tory Report. (Available through Publica- 



