Wave propagation in a constrained fluid layer bounded by an elastic half-space and its relevance in cochlear micromechanics

Wave propagation is investigated in a thin fluid layer bound by a rigid surface and an elastic half-space. Slow waves are possible if the fluid gap is small compared with the wavelength of the Rayleigh wave in the elastic half-space. The relevance of such a wave in cochlear micromechanics is discussed, which leads to the incorporation of the fluid viscosity and elastic loss into the wave equation. For typical parameters in the cochlea, the wave is dominated by the stiffness of the elastic half-space and the viscosity of the fluid, decaying significantly within a wavelength.