Influence of the osseous spiral lamina on the inner ear’s response to air- and bone-conducted stimulation

Recent studies have provided valuable insight into the anatomy and motion of the cochlear partition, particularly emphasizing the flexible nature of the osseous spiral lamina (OSL). However, whether in studies involving air- or bone-conducted stimulation, the OSL is often treated as a rigid structure, overlooking its potential impact on the cochlear macro mechanisms. In this study, we investigate the effect of the OSL’s flexibility by incorporating it as either a rigid or a flexible structure in a finite element model of the human inner ear. By applying both air- and bone-conducted stimulation, we found that the OSL’s flexibility significantly influences cochlear impedances, cochlear partition stiffness, and the differential fluid flow at the oval and the round windows. These results emphasize the importance of considering the flexibility of the OSL for an improved understanding of cochlear function and interpretation of experimental data on inner ear responses. [This work was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Project-ID 352015383 – SFB 1330 A4.]