The organ of Corti is one of the most organized tissues in the human body. It consists of four rows of hair cells interspersed by non-sensory supporting cells. The organized pattern of hair cells and supporting cells emerges from a disordered epithelium over a span of a few days. Although a lot is known about the genetic and biochemical processes underlying the development of the organ of Corti, the transition from disordered to ordered pattern is not well understood. In this project we use a combination of quantitative morphological analysis, time lapse imaging of cochlear explants, and mathematical modeling to elucidate the process that underlie the transition into an organized pattern. We show that the hair cells evolve to maintain a lattice like organization in a gradual manner. We find that intercalations and delaminations of supporting cells underlie the reorganization of hair cells. We develop a mathematical model that describes the transition from disordered to ordered pattern at the apical side of the OoC in terms of the mechanical forces that act on the cells. We suggest that global external pressure and local repulsion on hair cells are sufficient to drive the lattice-like pattern.