The inner ear is lined with two types of hair cells that help us to hear and balance. The cells respond to sound waves for hearing and head and body movement for balance. As we age, the cells are injured or die off, and our hearing and balance suffer as a result. Studies have shown that the hair cells in fish, frogs and birds can regenerate naturally. New research by scientists at the University of Washington and Southern Illinois University School of Medicine indicates that the hair cells involved with balance—called vestibular cells—may also be replenished in mammals. This could have