308 



AUDITORY BIOPHYSICS 



relations between the objective phenomena in the form of the acoustic 

 impulses, and the complexities introduced by the transmission mecha- 

 nism of the ear into the mechanical vibrations which are translated via 

 nerve impulses into pitch and loudness perceptions. The above inter- 

 pretations of the data appear to be consistent with a place theory of 

 hearing that does not employ the principle of simple resonance. 



460(W 



6900^ 



2300-J 



Fig. VII-25. The auditory coch- 

 lear pattern of a 700-cycle tone at 

 90 db. Numbers to 100 indicate 

 linear distances from the apex. 

 The length of the aural membrane 

 is taken as 100 units. Note the 

 positions and intensities of the 

 aural harmonics. (By courtesy of 

 H. Fletcher [1940].) 



Fig. VII-26. A nerve-deafness pat- 

 tern. The breadth of the cross hatching 

 indicates the degree of deafness. This 

 person can hear 2300 cycles because his 

 auditory pattern at 2300 cycles protrudes 

 through his deafness pattern. He does 

 not hear the aural harmonics at this 

 intensity level. (By courtesy of H. 

 Fletcher [1940].) 



A more systematic and consistent picture of the auditory processes is 

 presented by S. S. Stevens and Hallowell Davis in their monograph, 

 Hearing, Its Psychology and Physiology (John Wiley & Sons, 1938), 

 which the thoughtful student will enjoy reading to supplement the 

 above elementary presentation of an important field of research in 

 biophysics. 



BIBLIOGRAPHY 



1862 Helmholtz, H. v., Die Lehre von den Tonempfindungen, 1st Ed., Braun- 

 schweig. 

 1905 Shaw, P. E., Proc. Roy. Soc. London, A76, 360. 

 1908 Hardesty, I., Am. J. Anal., 8, 2. 

 1910 Kohler, W., Z. Psychol., 54, 241. 



