266 



VISUAL COMMUNICATION 



5. Visual systems are silent, except per- 

 haps for bells signalling a message, and 

 should not add to the general noise level 

 where silence is at a premium. 



6. Both sending and receiving time are 

 minimal. 



These potential advantages should render 

 visual communication systems, which dis- 

 play illuminated signal jewels, instrument 

 dials of a variety of kinds, and other types of 

 visual symbols directly to the receiver, of 

 great utility for interior communications in 

 submarines. They are most fully realized 

 in just those situations in which voice com- 

 munications become difficult. It is there- 

 fore urged that research on the properties 

 and practicability of such systems be in- 

 tiated, with the view of developing them as 

 methods of communication to supplement 

 many of the voice communication systems 

 now in use. 



Conclusion 



Improvement in communications may be 

 expected if research is performed on visual 

 techniques. Three areas seem in need of 

 research, and specific recommendations are 

 made with respect to them. 



1. The use of fluorescent sea-dyes is sug- 

 gested as a possible solution of the recogni- 

 tion problem. 



2. It is probable that studies of blinker 

 sending and receiving will reveal methods of 

 improving both speed and accuracy. 



3. Supplementary visual communication 

 systems should be developed, in addition to 

 the present auditory interior communica- 

 tions, with the view of eliminating many of 

 the difficulties now encountered in voice 

 communication. 



References 



The list of references given below is by no 

 means an exhaustive survey of the pertinent lit- 

 erature. Those interested in exterior com- 

 munication by visual signals, on which there is 

 an extensive literature, are referred to Fulton, 

 John F., Hoff, Phebe M., & Perkins, Henrietta 



T. A bibliography of visual literature 1939- 

 1944, and Supplement. New Haven: Yale Univ. 

 Press, 1945, pp. 201 + x. 



1. Bell Telephone Co. Technical aspects of 



visible speech. Bell Telephone System Mon- 

 ograph B-U15, pp. 89. (Reprinted from J. 

 acous. Soc. Amer., 1946, 17, 1-89.) 



2. Commander submarines Atlantic fleet 



Standard submarine phraseology, pp. 24, 

 (RESTRICTED) 



3. Crozier, W. J., & Wolf, E. Theory and 



measurement of visual mechanisms. VI. 

 Wave length and flash duration in flicker. 

 /. gen. Physiol., 1941, 25, 89-110. 



4. Hunter, W. S., & Sigler, M. The span of 



visual discrimination as a function of time 

 and intensity of stimulation. /. exp. 

 Psychol., 1940, 26, 160-179. 



5. Keller, Fred S. The radio code research 



project, final report of Project SC -88, OSRD 

 5379, OEMsr-830, Report 8, The Psycho- 

 logical Corp., July 25, 1945. 



6. Maninger, R. C. & Knudson, W. T. Tests on 



IMC and 7MC Intercommunication Systems 

 of the USS Perch. Columbia Univ., Divis- 

 ion of War Research, Feb. 17, 1944, (P42/ 

 R759). (CONFIDENTIAL) 



7. OSRD-NDRC, Division 17. Transmission 



and reception of sounds under combat condi- 

 tions. Summary Technical Report, Div. 17, 

 NDRC, Vol. 3, Washington, 1946. 



8. OSRD-NDRC, Division 16. Non-image form- 



ing infra-red. Summary Technical Report, 

 Div. 16, NDRC, Vol. 3, Washington, 1946. 



9. Potter, R. K., Kapp, G. A., & Green, H. C. 



Visible speech. New York: Van Nostrand, 

 1947, pp. 441 + xvi. 



10. Psychoacoustic laboratory. Harvard univ. 



Vocabularies for military communications in 

 noise. Aug. 25, 1943. (OSRD, No. 1919) 



11. Reed, J. D. A note on reaction time as a 



test of color discrimination. J. exp. Psy- 

 chol., 1947, 39, 118-121. 



12. Reese, T. W., & Volkmann, J. The discrimi- 



nation of visual number. (Abstr.) Min. and 

 Proc. 23rd Mtg. Armed-Forces NRC Vision 

 Committee. March 4-5, 1949, pp. 85-88. 

 (RESTRICTED) 



13. U. S. War Dept., Combined Commissions 



Board. Combined visual signaling (V/S) 

 procedure. FM-24-22, (short title CCBP-5), 

 12 May 1943. (RESTRICTED) 



14. U. S. War Dept. Combined visual signaling 



procedure. (Abridged version for radio 

 telephone (W/T)) FM-24-23, 12 May 1943. 

 (RESTRICTED) 



