The youngest age that someone can get a Cochlear Implant for hearing is 12 months of age.
It's a good idea for young children as young as 12 months old who are hard of hearing or deaf to get a Cochlear Implant to aid them in speech and language skills and development.
As long as the person is 12 months old or older then they may qualify and be a good candidate for the Cochlear Implant.
Not everyone is a good candidate for having a Cochlear Implanted though.