Captured here is an unusual moment, when Joanne Milne, deaf since birth as a result of Usher syndrome, hears sound for the first time in 40 years. Her cochlear implants were switched on March 24, and her mother recorded this video showing her daughter’s emotional reaction to the sound of her doctor reciting the days of the week, then the months of the year. Usher syndrome is rare, and genetically inherited; it affects about 3 to 6 percent of all children who are deaf. Milne is from Gateshead, England. Her mother told the UK’s ITV News that if the cochlear implant operation failed, Joanne would not have been able to use her old hearing aids again. This video has gone viral around the world.