This extract of a youtube video shows a 5 year old boy, Trever, who was born deaf but fitted with a cochlear implant early in life. What is remarkable about this video is how unremarkable it is. The things to note are that:
Trever's speech is quite normal for an American child his age. There is no sign of the slurred pronunciation that is typical of "deaf speech".
Trever can understand the speech of others well without having to attempt to lip read. Note that he carries on playing with this toys while maintaining the conversation.
In Trever's case the implant was clearly successful, but the auditory experience of cochlear implant patients is nevertheless poor compared to that of individuals with healthy ears.