A new theory of hearing / by C. Herbert Hurst.

  • C. Herbert Hurst
Date:
1895
Catalogue details

Licence: Public Domain Mark

Credit: A new theory of hearing / by C. Herbert Hurst. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    15/38 page 333
    its course—we are again driven by the difficulties of the physical problem to base an estimate on physiological considerations ; what that estimate is will appear later. The cochlear canals, however, are not only tapered but but also spirally coiled; and the basilar membrane is at the apex continued into the Keissnerian which runs from this point to the base of the spiral narrowing very gradually. When the wave reaches the apex of the cochlea it will pass on to the upper (Keissnerian) membrane, for at this point the lower canal is continuous through the helicotrema with the upper (scale vestibuli); and the middle canal ends blindly in the slightly dilated “lagena,” the wall of which is formed by the two membranes (upper and lower) which are here continuous with each other. The wave of the basilar will thus, starting from the base of the cochlea close to the fenestra rotunda, run forwards to the apex, round the wall of the lagena and down by the Eeissiierian membrane to the base of the cochlea. The elasticity of the Eeissnerian membrane being much less than that of the basilar, it appears certain that the displacement at each point will be greater than that of the corresponding portion of the basilar, and further the loss of energy of the wave will be greater for the movements involved being more extensive will involve more internal friction. The smaller waves will hence probably be almost lost before reaching the base, and the larger ones will, apparently, die out at the base in the form of small vortices or eddies of the perilymph gradually coming to rest by internal friction of the somewhat viscid perilymph. This is not the place to discuss the far greater effect of viscidity of a fluid in restraining vortical movements than in restraining wave-like movements which involve only a temporary and relatively small internal deformation (or
    No text description is available for this image
    No text description is available for this image
    No text description is available for this image