SUBJECT: Ph.D. Dissertation Defense
BY: Charlise Lemons
TIME: Friday, November 30, 2018, 11:00 a.m.
PLACE: Love Building, 109
TITLE: Examining Middle-ear and Tectorial Membrane Mechanics using Computational Models
COMMITTEE: Dr. Julien Meaud, Chair (ME)
Dr. Kenneth Cunefare (ME)
Dr. Alper Erturk (ME)
Dr. Karim Sabra (ME)
Dr. Wei Sun (BME)


The ear acts as a sensitive broadband receiver which transduces sound waves in the ear canal to electrical signals sent to the nervous system. Each of the many small components which comprise the ear are mechanically fine-tuned to detect faint sound throughout a wide range of frequencies. By studying the mechanics of different components of the ear, the mechanisms which allow for such remarkable abilities can be better understood. In this thesis, the mechanics of components of the ears of several species are investigated: specifically, the mouse tectorial membrane, the chinchilla middle ear, and the bullfrog eardrum are studied. This thesis aims to characterize, for the first time, the anisotropic material properties of the tectorial membranes of wild-type and genetically modified mice at auditory frequencies. Additionally, a circuit model of the chinchilla middle ear, absent in literature prior to this study, was developed. Using this model, this thesis aims to evaluate the influence of stiffness, damping, and inertial properties on middle-ear transmission characteristics. Lastly, in this thesis, a mechanical basis for the long group delay observed through the bullfrog eardrum is proposed.