Nucleus is a system combining an electrical simulation device that is surgically implanted behind a patient's ear, a processor that captures sounds, and an electrode array that relays the sounds to the brain. It is a direct descendant of the original cochlear implants, also known as Nucleus, developed by Dr Graeme Clark in Melbourne during the 1970s. Nucleus was the first cochlear implant to be approved by the U.S. Food and Drug Administration. The system is upgradable, for example by installing a new sound processor, without surgery. Cochlear's latest processor, Nucleus 6, was launched in 2013 after six years of development. It replaced the Nucleus 5 system. In 2011, the Nucleus 5 CI500 series internal implant was recalled with up to a 24% failure rate. In 2013, the Nucleus implant recorded 99% reliability over the last 8 years, more than any similar product.