Viscoelastic properties of the human tympanic membrane studied with stroboscopic holography and finite element modeling.

Viscoelastic properties of the human tympanic membrane studied with stroboscopic holography and finite element modeling.
Hear Res. 2014 Mar 19;
Authors: De Greef D, Aernouts J, Aerts J, Cheng JT, Horwitz R, Rosowski JJ, Dirckx JJ
Abstract
A new anatomically-accurate Finite Element (FE) model of the tympanic membrane (TM) and malleus was combined with measurements of the sound-induced motion of the TM surface and the bony manubrium, in an isolated TM-malleus preparation. Using the results, we were able to address two issues related to how sound is coupled to the ossicular chain: (i) Estimate the viscous damping within the tympanic membrane itself, the presence of which may help smooth the broadband response of a potentially highly resonant TM, and (ii) Investigate the function of a peculiar feature of human middle-ear anatomy, the thin mucosal epithelial fold that couples the mid part of the human manubrium to the TM. Sound induced motions of the surface of ex vivo human eardrums and mallei were measured with stroboscopic holography, which yields maps of the amplitude and phase of the displacement of the entire membrane surface at selected frequencies. The results of these measurements were similar, but not identical to measurements made in intact ears. The holography measurements were complemented by laser-Doppler vibrometer measurements of sound-induced umbo velocity, which were made with fine-frequency resolution. Comparisons of these measur...

Source: Hearing Research - March 19, 2014 Category: Audiology Authors: De Greef D, Aernouts J, Aerts J, Cheng JT, Horwitz R, Rosowski JJ, Dirckx JJ Tags: Hear Res Source Type: research