FURTHER READING 



Carthy, J. D.: Animal Navigation. London: George 



Allen and Unwin, Ltd., 1956. 



This popular and readable book describes the orienta- 

 tion and navigation of insects, fishes, birds, and whales 

 as well as those of bats and domestic animals. 



Fletcher, H.: Speech and Hearing in Communication. 

 New York: Van Nostrand, 1953. 



This thorough and somewhat technical book sum- 

 marizes the extensive researches carried out at the Bell 

 Telephone Laboratories and elsewhere on the physical 

 properties of speech, the mechanisms of human hear- 

 ing, and the nature of hearing losses and deafness. 



GriflSn, D. R.: Listening in the Dark. New Haven, Con- 

 necticut: Yale University Press, 1958. 



Many aspects of the natural sonar of bats, birds, and 

 porpoises are discussed more fully than in this short 

 monograph, including the many different types of bats 

 and their orientation sounds, their pursuit and capture 

 of flying insects, fish, and other food. There are 

 chapters on echolocation by bUnd men, and on the 

 acuity of echolocation achieved by bats, including 

 their ability to hear faint echoes despite the presence 

 of louder jamming noises. 



GriJBBn, D. R.: "Bird Sonar." Scientific American Maga- 

 zine, March 1954. 

 "More about Bat 'Radar.' " Scientific American Mag- 

 azine, August 1958. 

 These articles contain excellent illustrations and sup- 

 plement the chapters of this monograph dealing with 

 the natural sonar of bats and birds. 



Horton, J. W.: Fundamentals of Sonar. Annapolis, 

 Maryland: U. S. Naval Institute, 1957. 



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