Researchers close in on cure for deafness A CURE for deafness could be a step closer after experts successfully used human stem cells to treat a common type of hearing loss. The team turned the stem cells into ear cells which they transplanted into rodents believed to be deaf, with a 46 per cent success rate. The rodents were able to hear again less than a month after having the embryonic cells inserted. The breakthrough discovery could lead to new treatmnets and therapies to treat, and possibly cure, for hearing loss. Project leader Dr Marcelo Rivolta, of Sheffield University's Department of Biomedical Sciences, said: "We believe this is an important step forward. We have now a method to produce human cochlear sensory cells that we could use to develop new drugs and treatments, and to study the function of genes. And more importantly, we have the proof-of-concept that human stem cells could be used to repair the damaged ear. He said the model of hearing loss successfully treated by the scientists was similar to a human condition known as auditory neuropathy, a form of deafness in which the damage occurs at the level of the cochlear nerve. The condition is present in more than one in ten people with profound hearing loss. Auditory neuropathy is a type of deafness where the problem lies in connection of the hair cells with the brain. Patients can be born with it and there are cases due to a genetic defect where a few responsible genes have already been identified. There is also increasing evidence that environmental factors, such as jaundice at birth and noise exposure later in life, could increase the risks of developing the condition. Dr Ralph Holme, Head of Biomedical Research for the charity Action on Hearing Loss, said: "The research is tremendously encouraging and gives us real hope it will be possible to fix the actual cause of some types of hearing loss in the future. For the millions of people for whom hearing loss is eroding their quality of life, this can't come soon enough. The charity says 850,000 people are deaf or have a hearing loss in Scotland. The study, funded by the Medical Research Council and Action on Hearing Loss, is published in the latest edition of the journal Nature.