I : 4/ Sound and the Ear 



25 



progressively broader and thicker as one proceeds toward the apex of 

 the spiral. 



The basilar membrane is the seat of the organ qfCorti, shown in detail 

 in Figure 11. This organ contains the nerve endings. Thus one may 

 think of the organ of Corti as a neuromechanical transducer. (A trans- 

 ducer is a device which converts one form of energy to another form.) 



Outer 

 Hair Cell 



Tectorial 

 Membrane 



Vestibular 

 Lip 



Outer Tunnel 



Spiral 

 Ll * amenf Claudius C ^of 



Hensen 



Phalangeal Vas Phalangeal 



Q e ll s Spiralis Cells 



Tympanic Lip 



Auditory Nerse 



Figure II. Histology of the organ of Corti. After A. A. 

 Maximow and W. Bloom, Textbook of Histology (Philadelphia: 

 W. B. Saunders Company, 1957). 



Histologists have studied the organ of Corti in great detail. It seems as 

 if almost every cell has its own name. The diagram in Figure 1 1 shows 

 many of these. It includes Claudine cells, Hensen cells, inner and outer 

 hair cells, and the tectorial membrane. It is believed that the bending 

 of the hair cells in some way excites the nerve endings which are located 

 in the organ of Corti. 



The action of the inner ear intimately involves the nervous system. 

 The details are deferred to Chapter 6 which follows chapters on the 

 conduction of impulses by nerves and the electrical potentials of the 

 central nervous system. 



REFERENCES 



1. Hunter, J. L., Acoustics (Englewood Cliffs, New Jersey: Prentice-Hall, Inc., 

 1957). 



