The inability to open the collapsible Eustachian tube (ET) has been related to the development of chronic Otitis Media. Although ET dysfunction may be due to anatomical and/or mechanical abnormalities, the precise mechanisms by which these structural properties alter ET opening phenomena have not been investigated. Previous investigations could only speculate on how these structural properties influence the tissue deformation processes responsible for ET opening. We have therefore developed a computational technique that can quantify these structure-function relationships. Cross-sectional histological images were obtained from 8 normal adult human subjects with no history of middle ear disease. A mid-cartilaginous image from each subject was used to create two-dimensional finite element models of the ET's soft tissue structures. ET opening phenomena were simulated by applying muscle forces on soft tissue surfaces in the appropriate direction and were quantified by calculating the resistance to flow in the opened lumen (R_v). A sensitivity analysis was conducted to determine the relative importance of muscle forces and soft tissue elastic properties. Muscle contraction resulted in a medial-superior rotation of the medial lamina, stretching deformation in the Ostmann's fatty tissue and lumen dilation. Variability in baseline R_v values correlated with tissue size while the functional relationship between R_v and a given mechanical parameter was consistent in all subjects. ET opening was found to be highly sensitive to the applied muscle forces and relatively insensitive to cartilage elastic properties. These computational models have therefore identified how different tissue elements alter ET opening phenomena, which elements should be targeted for treatment and the optimal mechanical properties of these tissue constructs.