Fluid–solid coupling analysis of the whole spiral organ of Corti

Abstract

The complex fluid–solid coupling movement of macro–micro structures and lymphatic fluid in the cochlea plays a crucial role in the mechanism of sound perception in the human ear. However, previous studies have primarily focused on the macrostructure and overlooked the microstructure of the Organ of Corti (OC). In reality, the microstructure of the OC can regulate the vibration of the basilar membrane, which is important for sound perception. To address this, a three-dimensional spiral passive cochlear model containing a complete OC that conforms to the real physiology of the human ear was developed, but the significant amplification of its motion by the action of outer hair cells (OHC) in the living cochlea was not considered. The fluid–solid coupling calculations were conducted on this model, specifically examining the mechanical response of the OC microstructure and the pressure changes in the lymphatic fluid. The results showed that the lower stiffness structure in the OC has a lower stress level, which contributes to the realization of sound perception. As the frequencies increases, the region of peak stress and displacement in the OHC moves from the apex to the base of the cochlea, reflecting frequency-selective characteristics. The tunnel of the OC amplifies pressure waves at specific locations, enabling more accurate frequency recognition. Furthermore, the presence of the OC not only causes significant radial differences in lymphatic fluid pressure in the scala vestibule, but also enhances internal cochlear vibration, playing an undeniable regulatory role in the sound perception.Kindly check and verify edit made in article title.We have checked and verified the editing in the article title.