Compositions and provided to induce cells of the inner ear to renter the cell cycle and to proliferate. In particular, hair cells are induced to proliferate by administration of a composition which activates the Myc and Notch. Supporting cells are induced to transdifferentiate to hair cells by inhibition of Myc and Notch activity or the activation of Atoh1. Methods of treatment include the intracellular delivery of these molecules to a specific therapeutic target.
