This article is about a research that was done to help patients who are deaf using human embryonic stem cell. The article states that for the first time these cells can replace missing or damaged neurons in the hearing pathway. The researchers say this approach would one day aid more people who are deaf and will currently benefit from it than the technique of replacing a limb or body part by an artificial limb or part that is electronically or mechanically powered. The article also states that there is a cochlear implant that is a surgical treatment for hearing loss that works like an artificial human cochlea in the inner ear, helping to send sound from the ear to the brain. It is different from a hearing aid, which simply amplifies sound. This process helps with patients who have lost or damaged hair cells in the first sensory cells in the hearing pathway. But the procedure will not work for people who have lost the neurons that transmit the auditory information to the brain. Doctors can one day also use this new approach to use cochlear implants those people around the world who have lost both their hair cells and the signal-transmitting neurons.