Plight: The progress each person makes with a CI varies, but there are several factors that can help determine how well a person may do:
* Age/onset of hearing loss: While it is true that early implantation in infants and children increases the likelihood of success with a CI, it is also true that late-deafened adults can also receive significant benefit from a CI.
* Language development: Children and adults who are proficient in English are more likely to have greater success with a CI. Having said that, there are many prelingually deaf children and adults who have excellent English skills and do just as well -- if not better -- than those who are postlingually (late) deafened.
* Length/duration of deafness: I don't know how much (if any) hearing your girlfriend had while growing up, but even a tiny amount of residual hearing can help a person better understand what they hear with a CI. A person who has some auditory memory of sound (compared to someone who was born completely deaf) can take those experiences/memories and associate/apply them to what he/she hears through their CI.
* Brain's adjustment: There is some degree of brain wiring that goes on. Some people (for whatever reason) are better able to interpret/understand what they hear through their CI than others. This has nothing to do with intelligence or the CI itself -- it's just a difference in the way we process auditory information. Some people are better visual learners. Some are better auditory learners. Some people take longer than others to understand what they hear through a CI, but once they make that "connection" between what is seen and heard, progress can rival those who are able to understand speech from the moment their CI is turned on.
* Committment/dedication to learn how to hear with a CI: Some people who are implanted expect to understand speech the moment their CI is activated. Learning how to hear with a CI takes time and patience. The comparison between a baby who must crawl before he can walk is similar to the learning process with a CI. Listening and understanding what one hears must be done in small steps. For example, you can't expect to converse with people in a noisy environment until you're able to separate environmental sounds from speech.
As for myself --
I'm 34 years old and received a CI last December. I've had my CI activated for 5 months.
In terms of my hearing loss background, I was diagnosed with a mild hearing loss at age 3, but didn't wear HAs until age 15 for a moderately-severe loss. By age 25 my loss dropped to severe-profound and by age 34, it was profound.
Since I have been able to hear/understand speech until 2-3 years ago (when I lost what speech discrimination I had in my right ear -- left ear had no speech discrimination for the past 10 years), I have a strong auditory memory and know what speech sounds like.
Although I'm late-deafened, it took me 3-4 weeks before I could start to understand speech with my CI. Even then it wasn't complete understanding -- more like random words here and there depending on the person speaking.
I am now at the 5 month mark. At my 3 month evaluation I was able to undersand 96% of sentences in quiet and 90% of sentences in noise. Pre-CI, my percentages were 22% for sentences in quiet and 0% for sentences in noise.
As for music -- I love listening to music! I'm especially fond of instrumental and vocal music. Some rock and pop music tends to be "hit or miss" because the more instruments and voices there are, the more difficult it is for me to hear. Several instruments played at once sound like a cacophony of blurred sound. Since I've only been activated for 5 months, I don't know if this is something that will improve in time. The good news? Repeated exposure to music that I enjoy makes it sound better and better each time I hear it.
When listening to music with a CI, it is recommended that a person start by listening to music that they remember so they can associate a sound (for example, a steady drumbeat) to what they hear. I think this is excellent advice. Most of the music I used to enjoy before losing my hearing now sounds "normal" to me. In other words, a flute sounds like a flute and a clarinet sounds like a clarinet. Because I grew up with hearing and remember the way these instruments sound, they are easy for me to recognize when I hear them with my CI.
One of the most important things I'd like to suggest is that you don't let others discourage your girlfriend from getting a CI just because she has been deaf for a long time. There are many prelingually deaf adults who do very well with a CI.
In regards to your question about performance plateaus...While there is no *definite* plateau (because of the factors named above), some CI surgeons and audis notice that adults tend to do very well with their CI during the first 3-6 months, plateau at the 6th or 7th month, but steadily improve during the next 6-12 months. I would think that as long as a person uses their CI consistently and pairs together speech understanding with lipreading or sign (if one has these skills), they should not experience a significant decrease in their ability to hear/understand speech with a CI at 1, 2 or 3 years post activation.
Hope this helps!
May they............................not hear 
