Finite Element Modeling of an Uncoiled Cochlea Using Synchrotron Radiation-Phase Contrast Imaging

Abstract

The cochlea is the spiral shaped end organ of hearing that contains the basilar membrane (BM) which separates cochlear scalae. Although the entire BM vibrates during stimulation, it has been shown that the perceived sound pitch is linked to the location of maximum deformation along the BM. Current computational models adjust the BM Young’s modulus to match the Greenwood function. The objective of this study is to investigate the effects of a realistic cochlear shape on the tuned BM Young’s modulus. A finite-element model of an uncoiled cochlea was constructed. The cochlear dimensions were derived from Synchrotron Radiation-Phase Contrast Imaging (SR-PCI) scans. Material properties, and boundary conditions were taken from the literature, and the BM Young’s modulus was calibrated so simulation results matched the Greenwood function over the auditory frequency spectrum. The simulated location of maximal BM displacement matched the Greenwood function after tuning the BM Young’s modulus. This value differs from the calibrated value found in the literature. This difference could arise because an unrealistic rectangular cross-sectional geometry was used in the literature. Therefore, obtaining accurate Young’s modulus needs a more realistic geometry.