Since Georg von Bekesy laid out the place theory of the hearing, researchers have been working to understand the remarkable tuning properties of mammalian hearing. Because access to the cochlea is restricted in live animals, and important aspects of hearing are destroyed in dead ones, models play a key role in interpreting local measurements. Over the years our lab has progressively added more anatomical and physiological details to the modeling, always with the intent of interpreting experimental results. Examples are how cochlear coiling affects low frequency hearing, how the tectorial membrane introduces a second traveling wave that activates the outer hair cells and helps to excite inner hair cells, and how mechanical properties of tissues from the inner ear are important factors to be considered in development, repair, and normal function. Mechanical properties can be measured by the atomic force microscope (AFM) in our lab. These properties can reflect cytoskeletal changes as a result of altered protein expression in the cells of the inner ear that have been be altered by genetic manipulations. Thus our lab provides and important link between molecular genetics, cochlear development, and the physiology of hearing. Collaborations with the Yamada, Manoussaki, and Waterman labs involve of the use of the AFM to measure cell and substrate stiffness to assess how these factors influence cell motility, which has important implications for understanding development, pathophysiology, and the repair of tissues.

Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
National Institute on Deafness and Other Communication Disorders
Zip Code
Chadwick, Richard S; Lamb, Jessica S; Manoussaki, Daphne (2014) Stimulated acoustic emissions from coupled strings. J Eng Math 84:147-153
Lamb, Jessica S; Chadwick, Richard S (2014) Phase of shear vibrations within cochlear partition leads to activation of the cochlear amplifier. PLoS One 9:e85969
Szarama, Katherine B; Gavara, NĂºria; Petralia, Ronald S et al. (2013) Thyroid hormone increases fibroblast growth factor receptor expression and disrupts cell mechanics in the developing organ of corti. BMC Dev Biol 13:6
Gavara, Nuria; Chadwick, Richard S (2009) Collagen-based mechanical anisotropy of the tectorial membrane: implications for inter-row coupling of outer hair cell bundles. PLoS One 4:e4877
Manoussaki, Daphne; Chadwick, Richard S; Ketten, Darlene R et al. (2008) The influence of cochlear shape on low-frequency hearing. Proc Natl Acad Sci U S A 105:6162-6