The purpose of this study was to measure both middle ear stiffness and basilar membrane stiffness for the bottlenose dolphin (Tursiops truncatus) and compare these results with similar measures in other mammalian species. It was found that the point stiffness of the bottlenose dolphin basilar membrane has a gradient from 20 N/m near the base to 1.5 N/m near the apex and the middle ear has a stiffness of 1.37 x 106 N/m. These values are considerable higher than those reported for most terrestrial mammals, yet consistent with species specialized for high-frequency hearing.