One of the things that I find very difficult to relate to in regards to Cochlear Implants (CI) is how they sound compared to what I hear now. First of all I have had a hearing loss in all of my life. I therefore don’t know how sounds are supposed to be like. I cannot imagine how everything would sound if I could had a normal hearing.
As mentioned in a previous post I have a big loss of speech discrimination – which is a loss in the ability to discriminate between sounds. This means that it can be very hard for me to hear the difference between consonants – was the word “fact”, “cat”, “mat”, “fat”, “hat” or “lad”? This is probably where CI might be able to help me, as CI is said to be good at improving speech discrimination and help me hear sounds that I currently cannot hear.
CI replaces the normal way to hear by using an electronic device that communicates directly with the auditory nerve. During the surgery a small wire is implanted into the cochlea and it is this wire that sends small electric impulses into the nerve from a number of electrodes. In a very high level perspective you could say that each electrode corespond to a given tone. The wire that is put into the cochlea is very short and it is therefore very limited how many electrodes they can put on the wire. The solution to this problem is to do so that each electrode represents multiple frequences. The audio spectre is therefore divided in to sections that will be “played” through one of the electrodes. In the materials I have read it turns out that most CI solutions today have between 16 and 24 electrodes.
I find it very difficult to imagine hearing through so few divisions of the sound!
But even though there are so few sound channels it should be possible to hear the difference between many more sounds. Depending on the CI solution people have received and their training it should be possible to hear the difference between more than 400 different frequences (source)
But how does it sound compared to what I can hear today?
This is of course a question that cannot be answered without trying it. But you cannot just try CI and go back to the hearing you had before. It is therefore very difficult decision to make.
I have found a range of websites and Youtube videos that contain simulations of how CI sounds. These simulations should of course be taken lightly because it really isn’t possible to compare a computer simulation through a set of computerspeakers with the sounds that CI users actually hears. I have seen CI-users comment on these simulations that they can clearly hear that these simulations have a very bad sound compared to what they can hear.
If you want to hear some of these simulations then please remember that it requires a lot of training to hear with CI – so for the untrained ear it will be very difficult to understand what is said in these simulations.
Simulations of the sounds through Cochlear Implant (CI):
http://www.kfs.oeaw.ac.at/content/blogcategory/122/513/lang,8859-1/
http://www.hei.org/research/shannon/simulations/
http://mustelid.physiol.ox.ac.uk/drupal/?q=prosthetics/noise_vocoded_speech
http://ent.uci.edu/cochlear%20implant.htm
http://www.healthaffairs.uci.edu/hesp/simulations/simulationsmain.htm
Find more on google:
https://www.google.dk/search?q=cochlea+implant+simulation
When I hear these simulations it is very hard for me to judge them as I also hear them through my Hearing Aids and with the hearing loss and loss of speech discrimination that I have. The simulated sound can therefore not be compared with the sound that a CI-user will be able to hear and it will without be very bad compared to what I hear with my current hearing aids.
But what strikes me most when listening to these simulations is that the sound is have much more high frequencies than low frequences. I also feel that the music samples makes me very skeptical as I think they lack a lot details and nuances.
I know that CI primarily is developed to improve the audio frequencies that are used in speech. Music through CI is secondary but the developers have started to focus on this. When reading about other peoples experiences of CI with music I get the impression that people can enjoy music. But in my opinion it doesnt change the fact that something will be lost when comparing with the more analog sound you get through a hearing aid or with normal hearing.
But could I not imagine getting CI?
Yes I could.
As earlier mentioned my biggest problem today is my big loss of speech discrimination that makes it difficult to hear in many situations. I am therefore very interested in finding solutions for this issue that can have very big consequences in my social life and in work situations. CI is optimized to improve speech recognition. In some of the materials I have read it is said that people with CI and proper training can achieve a speech discrimination of 80 % or even more. On paper this is much better than my LOSS of speech discrimination which is on 80%. I am therefore very interested in investigating whether or not CI could be a solution for me.
That something might be lost in relation to enjoying music and all the nuances of sound is not as important as the advantages that might come in being able to hear what people say.
I am looking very much forwards to hear if the “experts” think that I would be able to benefit from getting CI. In about 1½ week I need to go by an ear specialist to get a reference to the audiology department where they can help me with clarifying this question. Maybe this process will suddenly go very fast.