How would a pre-lingual adult CI candidate, who has most likely been orally educated, learned speech with hearing aids, experience a "complete life change" with a CI? I've personally seen some qualitative changes such as being able to use the phone and hearing speech better but "complete life change" is a bit strong. I still function as a person who has difficulty in hearing at times, even though the degree has changed.
Are you refering to pre-linguals who have never heard sound or had only limited benefit from hearing aids prior? In this case, I'd agree.
