A MODEL TO ILLUSTRATE THE PROBABLE ACTION 

 OF THE TECTORIAL MEMBRANE 



IRVING HARDESTY 



From the Deparlmenl of Anatomy oj the Tulane University of Louisiana 



SEVEN FIGURES 



In some studies of the cochleae of the pig, the writer ('08 and 

 '15) became convinced that the tectorial membrane and not the 

 basilar membrane is at least the chief vibratory structure in the 

 mechanism for hearing. With this conviction, the construction 

 of a model was undertaken with the hope that it might illustrate 

 something of the possible behavior of the mammalian tectorial 

 membrane when energy represented by sound waves is imparted 

 to the fluid in which it lies. 



Of the many experiments with apparatuses and the several 

 models described by others, none have attempted to reproduce 

 the form and arrangements of the parts of the actual auditory 

 apparatus and but little of the conditions under which these parts 

 are supposed to act in the animal. It seemed to the author 

 that more instructive indications of the process of hearing might 

 be obtained with a model in which the outer, middle and inner 

 divisions of the peripheral part of the auditory apparatus are 

 represented and the forms and relative arrangements of the 

 structures comprising each division imitated, and a model to 

 which might be applied the disturbances giving rise to sensations 

 of sound in the actual ear. The construction of such a model 

 must necessarily be preceded by detailed studies of the structures 

 of the ear and especially of those structures considered acted upon 

 by sound waves in a way to arouse the various sound impulses 

 in the auditory neurones. Also it seemed advisable that the stud- 

 ies of the structures be carried to the labyrinths of adult animals, 

 rather than confined to those of foetuses, and the writer's paper 



471 



