Sphere-forming cochlear stem cells/progenitors have recently been isolated from the postnatal mouse organ of Corti. However, self-renewal of the cochlear progenitors remains to be elucidated. Here we demonstrate the renewable cochlear neural progenitors from the postnatal Immortomouse organ of Corti containing a temperature-sensitive SV40 that have the potential to differentiate into hair cell-, neuron-, and supporting cell-like phenotypes under the guidance of sonic hedgehog, epidermal growth factor, retinoic acid, and brain-derived neurotrophic factor, herein termed SERB. This work provides a rationale for using cochlear neural progenitors in possible cell replacement of lost hair cells and neurons in degenerative hearing disorders.