A new study shows, like those before it, that cochlear implants make life better for deaf kids, and the sooner they get them, the better. The point is that during the time before the implant, the kid isn't hearing language right, which affects their ability to use it.
Kids who got an implant before 18 months of age reached a particular language development milestone at 36 months, compared with normal hearing kids' 27 months. Kids who got an implant after age 3 reached the milestone 2 years later, and the actual time per kid was related to when they got the implant.
Normally I give a lot of leeway to parental discretion, but this is a case where dithering hurts the kid. If you have a deaf kid, talk to your doctor about cochlear implants today.