3D Computational Modeling of Blast Wave Transmission from External Ear to Cochlear Hair Cells.

The human ear is a complex biomechanical system that transduces sound or blast waves into cochlear hair cells for sensory perception. Understanding the full pathway of mechanical energy transmission, from the external ear through the middle ear and into the cochlear sensory structures, is essential for advancing clinical surgical treatment, hearing protection, and auditory prostheses. Over the past two decades, finite element (FE) modeling has become a powerful tool for analyzing ear mechanics, offering insights that complement experimental limitations. This chapter summarizes major developments in 3D FE models of the human ear, from macroscale simulations of sound and blast wave propagation to microscale modeling of cochlear biomechanical responses. The macroscale models based on anatomical details of the human ear with the coupled fluid-structure interaction (FSI) analysis are reviewed first. The evolution toward multiscale models that couple cochlear partition motion with detailed representations of the organ of Corti (OC) and hair cells is then described. The integration of macroscale and microscale models enables simulations of blast-induced cochlear trauma and acoustic fatigue failure. Together, these developments offer a comprehensive framework for understanding auditory biomechanics across different length scales. This chapter is organized into two parts: Part I focuses on macroscale modeling of sound and blast wave transmission; Part II discusses multiscale and microscale modeling with applications to cochlear damage prediction.