While hearing aids are relatively speaking uncontroversial, the internal portion of a cochlear implant requires surgery, which of course entails risk. There is a significant period of rehabilitation as the brain learns to make sense of a totally new type of electronic input, and the external processor itself is slightly larger and more visible on the head. Deaf adults can of course make this decision for themselves, but increasingly the recommendations are for parents to implant their children in infancy as this generally produces the best outcomes. Even in the past few years, the age of recommended implantation for severely to profoundly deaf babies has dropped to nine months. Their astonishing success rate in aiding the understanding of speech has meant a new generation of deaf adults are emerging who do not use sign language in the way they would have done only a few decades earlier.

While for some this is one of the great advances of modern medicine, for others it is a deeply worrying evolution. The new technological possibilities and their swift adoption have understandably caused widespread consternation in Deaf communities globally. The future of their complex and rich visual languages is endangered by the developments, as well as the communities and ways of life that stem from them. These are genuine and valid concerns, and ones that are rarely addressed in moderate, bipartisan terms. There are also broader ethical concerns raised by surgical intervention of this kind on children whose lives are not threatened, and who are not in a position to request or consent.

Why is the case of cochlear implantation so different from other parallel medical situations that a parent has to navigate? Why is it controversial in the way that an artificial limb or cornea transplant is not? Unlike the parent of a child with vision loss who pursues laser surgery in an uncomplicated way, the parent of a deaf child is implicated in a much larger politico-cultural struggle. To my outsider’s eyes, a lot of this was not the tangled snarl of identity politics, but seemed largely to stem from a fundamental disagreement over the metaphysics of deafness. Whereas the hearing world, hand in hand with the medical one, has conceptualised deafness as a sensory deficit that can be relatively effectively ‘restored’ – albeit partially, temporarily and imperfectly – parts of the Deaf-World argue that this approach demonstrates an outdated pathologisation of difference.