Guest guest Posted October 15, 2004 Report Share Posted October 15, 2004 Hi , Welcome to the list! CI mapping is when the audiologist tunes the cochlear implant. Each implant user has a uniquely different " map " computer program stored in their CI processor (the part worn on the belt, in a harness, or behind the ear.) Basically, the point of mapping is to make each individual electrode in the implant loud enough so the person perceives sound, but not so loud that he or she finds it uncomfortable. For example, my son has a Nucleus 24 implant which has 22 electrodes in the cochlea. The ones furthest in the spiral correspond to the lowest tones, and the ones furthest from the center are the highest tones. (Small possibility I've got this this backwards, but it doesn't really matter for this explanation.) So what the audiologist does is, electrode by electrode, figure out how much power (voltage? current? I am not sure) is required to let the person hear the tone of that electrode. This is called the Threshold, or T-level. Then he or she figures out what is the MOST power the person can tolerate at that electrode before it gets too loud. This is called the Comfort Level or C-level. Older children and adults just tell the audiologist when they hear the tone and when it is too loud. For very young children, there are various automated tricks to setting these levels. It is best if there is a range between the T and C levels for each electrode so the sound is more rich and a person better perceives volume differences. Once all the levels have been set, the audiologist will turn the electrodes all on, and let the computer program in the processor decide which electrodes to fire depending on what the incoming sound is. This is the part where kids sometimes cry because it can seem loud. But don't let it worry you -- they get used to it and begin to love their CI very soon. In the beginning (the first few weeks and months), a child will have a lot of mappings as the ear and brain adjust to listening. The child's T and C levels will change, and should be adjusted frequently. After the first year, people usually go back for map adjustments 2 or 3 times a year. (Some adults less often.) If this is still confusing, don't worry, it is! After a bunch of mapping sessions it will make sense! Occasionally, when my son starts making an unusual number of listening mistakes, it is because he needs a new map. (It happens just due to changes in body chemistry -- who knows why.) For us, fortunately, this does not happen very often. Other people may need more frequent map adjustments. Oh, I think the word is actually spelled MAPping. I think the M.A.P. stands for something but I don't know what. Lydia Mom of , Nucleus 24 Contour 1/01 at age 4. Now approaching 8 years old (and 4 years implant use.) Uses 3G behind-the-ear (BTE) processor and Colin, almost 11 years old, hearing > My son will be getting a ci in about 5 months. What is ci mapping? Do they map the inside of the ear? Thanks for your help! > > Quote Link to comment Share on other sites More sharing options...
Guest guest Posted October 15, 2004 Report Share Posted October 15, 2004 Lydia.... Thanks for the very thorough MAPping explanation. Although I know most this info, I never could have laid it out so well. Thanks, Debby Mom to Lindsi...Med El on 9/23/04.... Turned on in 11 days! Quote Link to comment Share on other sites More sharing options...
Guest guest Posted October 15, 2004 Report Share Posted October 15, 2004 Thanks Lydia, that is a wonderful explaination! I do understand better. Lydia Gregoret wrote: Hi , Welcome to the list! CI mapping is when the audiologist tunes the cochlear implant. Each implant user has a uniquely different " map " computer program stored in their CI processor (the part worn on the belt, in a harness, or behind the ear.) Basically, the point of mapping is to make each individual electrode in the implant loud enough so the person perceives sound, but not so loud that he or she finds it uncomfortable. For example, my son has a Nucleus 24 implant which has 22 electrodes in the cochlea. The ones furthest in the spiral correspond to the lowest tones, and the ones furthest from the center are the highest tones. (Small possibility I've got this this backwards, but it doesn't really matter for this explanation.) So what the audiologist does is, electrode by electrode, figure out how much power (voltage? current? I am not sure) is required to let the person hear the tone of that electrode. This is called the Threshold, or T-level. Then he or she figures out what is the MOST power the person can tolerate at that electrode before it gets too loud. This is called the Comfort Level or C-level. Older children and adults just tell the audiologist when they hear the tone and when it is too loud. For very young children, there are various automated tricks to setting these levels. It is best if there is a range between the T and C levels for each electrode so the sound is more rich and a person better perceives volume differences. Once all the levels have been set, the audiologist will turn the electrodes all on, and let the computer program in the processor decide which electrodes to fire depending on what the incoming sound is. This is the part where kids sometimes cry because it can seem loud. But don't let it worry you -- they get used to it and begin to love their CI very soon. In the beginning (the first few weeks and months), a child will have a lot of mappings as the ear and brain adjust to listening. The child's T and C levels will change, and should be adjusted frequently. After the first year, people usually go back for map adjustments 2 or 3 times a year. (Some adults less often.) If this is still confusing, don't worry, it is! After a bunch of mapping sessions it will make sense! Occasionally, when my son starts making an unusual number of listening mistakes, it is because he needs a new map. (It happens just due to changes in body chemistry -- who knows why.) For us, fortunately, this does not happen very often. Other people may need more frequent map adjustments. Oh, I think the word is actually spelled MAPping. I think the M.A.P. stands for something but I don't know what. Lydia Mom of , Nucleus 24 Contour 1/01 at age 4. Now approaching 8 years old (and 4 years implant use.) Uses 3G behind-the-ear (BTE) processor and Colin, almost 11 years old, hearing > My son will be getting a ci in about 5 months. What is ci mapping? Do they map the inside of the ear? Thanks for your help! > > All messages posted to this list are private and confidential. Each post is the intellectual property of the author and therefore subject to copyright restrictions. Quote Link to comment Share on other sites More sharing options...
Guest guest Posted October 15, 2004 Report Share Posted October 15, 2004 Dear and Debby -- Glad to help! You will love the implant! I just wanted to clarify one little thing I wrote. It's sort of obvious, but I didn't want to worry anyone unnecessarily: >... This is the part where kids sometimes cry because it can seem > loud. But don't let it worry you -- they get used to it and begin > to love their CI very soon. I meant only when they are hearing with the implant for the very first time! The following mappings are not a shocking surprise like the first one can be. And some kids don't even cry at the first one. With regards to the signals, while it is true that the signals are artificial and electronic, the process not entirely different from how natural hearing works. When nerves fire, whether that be hearing nerves or the nerves that tell our brains we have touched something hot, they still do it with electrical impulses. I am always amazed at the subtle qualities of sound that can detect with his cochlear implant. One of the most amazing things was something he said a couple of months ago. We have a friend named . is English and, to us, her American friends, has an exceptionally charming accent and lovely voice. We've never talked about 's voice or accent that I can remember. However, one day said to me out of the blue, " Mom, don't you just love the way 's voice sounds? " " Yes! I do! " I said, in amazement. Lydia , almost 8, implant at age 4 1/01 Colin, almost 11, hearing Quote Link to comment Share on other sites More sharing options...
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