Most of us know children are too young to know what it is like to have something permanent. Since they're too young to know what's like to have something permanent, they're also too young to make a decision for something permanent.
Don't get me wrong, cochlear implant is good for some people but I don't believe it should be given to a child who's incapable of fully understanding. Most parents fear that their child with hearing loss will not fit into the world. They fears that the child would feel loneliness not be able to communicate with their classmate. And kids do sometime make fun of being deaf. They wouldn't want their child to feel that way.
That's why they have special accommodations for deaf children all over the states. Deaf are not the only children that feel lonely and they can still write back and forth and use physical gesture to communicate. Not only that but they have interpreters that can hear and sign for deaf students and teachers.
I have seen deaf people have friends that can hear. So being deaf is not an excuse for being lonely. The problem still remains about put cochlear implant into the child's head. Putting cochlear implant make more limitation than being deaf or without one. For example, anyone with CI (cochlear implant) is limited to some sports. They shouldn't be doing soccer, boxing, martial arts (with partners), playgrounds, trampolines, or anything that involve getting your head hit without a helmet. It also can be disadvantage around special environment when they're close to neon lights or radar detector. It can cause a loud buzzing sound to them. So they got to stay away from Las Vegas.
So why take something away from them that they would love to try or love to do? I have tons of friends that enjoyed being deaf. I, myself enjoy having hearing loss because it got me to have a lifetime friends and unforgettable people that share the same background as me. Once you put that CI in your child it's in there for life. I believe it's best to wait until they're old enough to fully understand the differences.
"Deaf people can do anything but hear." - I King Jordan