A genetic cure for hereditary deafness looks possible. Here's the objection: "Members of the signing Deaf community argue that research which aims to eliminate or cure deafness is a form of cultural genocide. The argument goes like this: the use of gene therapy to cure hereditary deafness would result in smaller numbers of deaf children. This, in turn, would reduce the critical mass of signing Deaf people needed for a flourishing community, ultimately resulting in the demise of the community."[1]
A similar argument has been made against cochlear implants, which already work in many people who are totally deaf. "According to the National Association of the Deaf (NAD), “An implant is not a ‘cure’ and an implanted individual is still deaf,” which makes us realize the crux of the issue. Those who are deaf and hard of hearing consider these disabilities to be aspects of their identities. By using the cochlear implant, they are essentially killing a piece of themselves that they’ve lived with from the day they were born."[2]
Think about that for a while.
[1] https://impactethics.ca/2017/03/02/gene-therapy-a-threat-to-...
[2] https://www.theodysseyonline.com/cochlear-implant-controvers...