Author:

Keywords:

1804821N#56522649, 11D5723N|11D5725N#56446257, G088619N#54969805

Abstract:

Hearing research extensively focused on the response of the organ of Corti (OoC) and basilar membrane (BM), to sound-induced vibrations. Those two components are crucial elements in the traveling wave theory proposed by Nobel laureate Von Békésy. This theoretical framework suggests that sound vibrations induce a traveling wave pattern along the BM, with frequency-specific maximal displacements. Technological advancements such as optical coherence tomography (OCT), have allowed for renewed insights into cochlear anatomy and motion. Here, we use OCT to investigate human cochlear partition structures, including the OoC, BM, sensory epithelium (SE), osseous spiral lamina (OSL), cochlear partition bridge (CPB), and Spiral Limbus (SL). Using OCT vibrometry on 5 fresh postmortem human cochleae (5 ~ 24h post-mortem), we measured the velocity of these structures across a frequency range of 500 to 6000 Hz. A linear mixed model (LMM) analysis revealed a significant interaction effect between frequency and anatomical structure, indicating frequency-dependent velocity variations. Notably, the stapes exhibited consistently lower velocity compared to the cochlear partition, highlighting the potential hydraulic amplification mechanism the cochlea contributes to. Furthermore, our findings underscore the importance of considering the entire cochlear partition in modeling cochlear responses.