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Choosing a Cochlear Implant?
sydsavage asks: "My mom, who is profoundly deaf, has finally qualified for a cochlear implant. She is having the procedure done at the University of Minnesota, and is scheduled for surgery in early March. The doctors have left it up to her to choose between two different implants. The differences between them are highly technical, and well above her level of comprehension. So she decided to ask her geek son to take a look at the differing technologies. Unfortunately, I'm a systems administrator, not an audio engineer or signal processing guru, and reading
up on the technologies made this fact blaringly obvious to me. About the best I can tell her is one has more accessories available, as any good geek could ascertain. While this may have an impact on her decision, at the end of the day, she just wants to be able to hear better. Are there any slashdot readers with first or second hand experience with these two devices? Any signal processing engineers that would like to weigh in on the different technologies involved?"
"The two implants that are available to her are the Clarion, manufactured by Advanced Bionics, and the Nucleus, made by the Australian firm Cochlear.
The Nucleus system is the one with more bells in whistles, such as the ability to interface to FM systems for hearing impaired that are found in museums, auditoriums and theaters. It can also plug into an audio out jack of a tv, stereo or computer. It also has a built in 'tele-coil' for use with phones that are design to work with hearing aids.
My mother and I would both like to say thank you in advance for your help in making this life changing decision."
>What joke of a doctor tells the patient to look at two implants
> and chose based on highly technical differences
It is quite possible that the doctor did not do this. My advice: visit the doctor with your mom to hear for yourself what he is asking your mom to do. There probably is a good reason that he gives her a choice, for instance:
- the two devices differ in cost (to your mom)
- one will cost here more learning effort, but will eventually give here better hearing (AFAIK, cochlear implants never 'just work'; your mom will require training to use one)
- neither of them is better than the other in all environments
- one of them allows/requires her to adjust some parameters for optimum playback, the other lacks those fine controls, making it easier to use at the cost of some sound quality
I am Deaf.
I don't pretend to be an expert on Cochlear implants, but you do have to realize that there is a lot more to "curing" deafness than simply picking the best hearing aid due to its technical specs.
As an analogy, take someone who's been doing graphics work on a Mac for years, decades and suddenly tell him that if he wants to keep his job, he has to become an OpenVMS system administrator and maintain the company's equipment without the benefit of a GUI.
Don't pick an implant on the basis of what it says it can do. Pick an implant on the basis of what your Mom wants to do, and is comfortable doing. For example, the Nucleus system boasts of being compatable with tele-coils. Most conventional hearing aids today are compatible with tele-coils, and within the next five years or so, all "new" models will be.
Furthermore, in order to use tele-coils, we usually have to flick a tiny switch on our hearing aids to switch from "conventional" sounds (that use sound waves) to induced sounds. Cochlear implants have the same switch or something very similar. For the elderly, manipulating that tiny little switch is usually a pain in the ass. Guess what the predominant preference is? An amplifier that can be plugged directly into the telephone line - or better yet, phones that come with sufficiently loud speakers built in.
Your next step should be to speak to an audiologist if you have not done so already. What you need to know is what frequencies you (or your Mom in this case) tends to listen for. Like any decent home stereo system, implants are optimized for a certain range and stutter, hiss, whistle, whatever outside of that range.
As an hypothetical example, it may be that she cannot hear high frequencies at all, but she can hear bass tones easily. If that's the case, you want one that will "magnify" those high frequences until she can hear them, and give maybe just a slight boost to the lower frequencies. Then you can select a model that will give you the most flexibility in compenstating for her deafness.
Hi,
n .h tml
I wouldn't worry too much about how they work. Lots of treatments help people every day, without the doctors even knowing how they work! I'd try to find out about any proper clinical trials done - that's the best starting point for evaluating the options. Unfortunately, I've no idea what proper research has been done in this area, but I suggest you start hunting around - I'm sure there'll be info out there on the net.
Here's one starting point:
http://www.geocities.com/cicentral/ci_compariso
The key thing is to place little credence in personal testimonies and theories. By theories I mean claims of the type 'Because our device has a foo, it will cause less irritating bar'. Assuming you know nothing about the medicine and technology involved, such claims sound perfectly reasonable, but remember they are actually as useful as claims like 'Because Intel processors run at a higher clock speed, tasks like word processing become easier', or even 'Because we use XML, our software is more intelligent'. To a non computer literate person, such claims sound reasonable.
Personal testimonies are valuable, but remember how different one human is to another. It's very tempting in a sea of uncertain research to latch on to someone saying 'My aunt Maud had a type one device for 3 years, and it caused all sorts of problems - but now she's on a type 2 device it's much better'. That's effectively a single datum, and in the larger picture it doesn't mean much. Of course once you have enough of them, then it means more...
When reading info on the net about this stuff, ALWAYS look for references (citations of journal articles etc) to back up any claims. Be suitable wary of 'expert opinion' - Medical experts as just as biased as computer experts - and think how many of those say things that you think are rubbish!
If you are really serious about this kind of research, the US Govt. provides an excellent resource:
http://www.ncbi.nlm.nih.gov/PubMed/
Good luck with your hunt!
-----
.. who works in the office of hearing services for the Dept of health here in Australia:
;)
There are two 'components' to a cochlear implant - generally characterised as 'the outside bits' and 'the inside bits'.
The outside bits are changed on a moderately regular basis as technology improves. The inside bits (which are implanted), obviously don't get changed all that much.
Her recommendation is to choose the technology that makes it easiest (and cheapest) to change the outside bits - as although there are minimal technical differences between the two options at the moment, if one is much easier to 'upgrade' than the other, you'll get much better service long term on that one.
Dunno about you.. but there's something wierd about the concept of booking your mum in for an upgrade...
My friend recommends having a look at the web site of the Australian National Acoustics Labs. They're a research arm of Australian Neuroservices, and have a fair bit of info on this sort of stuff.
Red.
I'm a neuroscientist by trade (well, no, actually I paid good money). I used to work for the Language Section of the National Institute on Deafness and Communications Disorders. I had to know a lot about these things technically and biologically. Also, my field of interest happens to be signal analysis, and that's at the heart of these devices. Also, I was an sign language interperator and considered myself a member of the Deaf community, a social distinction which might have bearing here. I'm not a physician, but I reckon I know enough to give my opinion mand have it considered informed.
.01 total harmonic distorion is good. One with .001 THD is better. But your average stereo speaker has about 3% THD, making the point moot. If the cost between the devices were great, I'd consider the cheaper.
/. journal for my email should you wish to email with questions.
You say she's profoundly deaf. Since when? If a long time, she may not adapt well no matter how good the device. The less sophisticated may be good enough then.
If she's been deaf a long time, does she socialize with other deaf people? If so, be aware some of them look on implants as a kind of betrayal. Those whose first language was American Sign Language consider themselves a unique culture and consider their condition and method of communication to be equally good as any other. Some very vocal (pardon the pun) types become quite irrate if someone they know steps outside their culture by getting an implant. I don't claim to understand exactly, but I've observed it.
Technically, these two devices probably perform equally well. The Clarion has superior characteristics, but the difference may be measureable in the lab but not the ear. The Clarion has more channels, that is more different frequency bands, and so would probably produce more "natural" sound. (To think of channels, consider the slider switches on an equalizer on a stereo. Each handles a specific range of frequencies. The more sliders there are, the finer the divisions across the sound spectrum.)
As mentioned elsewhere, Rush Limbaugh has a Clarion. I know he's pleased with the results, and he's a professional communicator.
The Nucleus has a removeable magnet. This could be important should your mother ever need to have an MRI. With either device, she'll need to wear a medical alert bracelet saying she has some implanted metal. An MRI uses a large, powerful moving magnet. If you expose a piece of metal to the field it can turn into a little food processor blade spinning around where it ought not. Should she ever be sent to the emergency room unconscious, they'll need to know not to do this to her. The Nucleus will give them the ability to should she need it.
If I were getting one and they cost the same, I'd get the Clarion. In a given ear, the end result will probably be better with that device. However, the differences between ears and neural systems are so much grteater that this may hardly matter. It may be better than the ear can make use of. Think of stereo systems. An amplifier with
A last thought: learning or relearning to hear will require a lot of exercise in order for neural plasticity to do its job. That means exposure. Also, if she's been reading sign language, those whove; been communicating with her should continue to use it even though she may now be able to hear. The resulting associations will help her learn/relearn faster.
Feel free to check my
"I may be synthetic, but I'm not stupid." -- Bishop 341-B