Feed-forward/Feed-backward Mechanical Amplification in the Mouse Cochlea

J. Soons[1,2], C. Steele[2], S. Puria[2]
[1]Lab of Biomedical physics, University of Antwerp, Antwerp, Belgium
[2]Department of Mechanical Engineering, Stanford University, Stanford, USA

Sound vibrations are collected from the external environment by the eardrum and are guided to the basilar membrane in the cochlea. Pressure differences in the two scalae of the cochlea result in a traveling wave on the basilar membrane. The tiny displacements are detected by the deflection of thousands of hair cells, situated along this membrane. It is hypothesized that some 3/4 of these hair cells, the outer hair cells, work as microscopic energy pumping motors, resulting in amplification of the basilar membrane motion. It still remains to be understood how thousands of these outer hair cells work together, resulting in the high sensitivity and frequency selectivity of mammalian ears. Here we present our first modeling results using COMSOL Multiphysics®.