Department of Biomedical Engineering, National University of Singapore, 21 Lower Kent Ridge Rd, Singapore, 119077, Singapore.
School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
Biomech Model Mechanobiol. 2018 Dec;17(6):1731-1740. doi: 10.1007/s10237-018-1052-5. Epub 2018 Jul 26.
For better understanding of bone-conducted (BC) hearing, a mechanical BC model is formulated using the Wentzel-Kramers-Brillouin (WKB) method. The BC hearing can be generally described by three main mechanisms: (1) cochlear fluid inertia, (2) in-phase motion of the outer bony shell, and (3) out-of-phase motion of the outer bony shell. Specifically, the second and third mechanisms can be identically explained by symmetric pressure compression-expansion and anti-symmetric compression-expansion, respectively. In this study, simulation results show that both the symmetric and anti-symmetric compression-expansion modes become significant at frequencies above 7 kHz while the fluid inertial mode is dominant at lower frequencies. The density difference between the scala fluid and soft cells of basilar membrane and the amplitude of the anti-symmetric compression-expansion input are identified as the difference between the air conduction and bone conduction. The natural frequency of the cochlear duct wall determines the magnitudes between the three mechanism and is approximated to be in the order of 10 MHz and above.
为了更好地理解骨导（BC）听力，我们使用 Wentzel-Kramers-Brillouin（WKB）方法建立了一个机械 BC 模型。BC 听力通常可以通过三个主要机制来描述：（1）耳蜗液惯性，（2）外骨壳同相运动，以及（3）外骨壳异相运动。具体来说，第二和第三机制可以分别通过对称的压力压缩-膨胀和非对称的压缩-膨胀来完全解释。在这项研究中，模拟结果表明，在频率高于 7 kHz 时，对称和非对称的压缩-膨胀模式都变得非常重要，而在较低频率时，流体惯性模式占主导地位。耳蜗管壁的密度差和基底膜软细胞之间的密度差以及非对称压缩-膨胀输入的幅度被确定为空气传导和骨传导之间的差异。耳蜗管壁的固有频率决定了三个机制之间的幅度，大约在 10 MHz 及以上。
