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."

Comments

Differences? Not a lot.

[DynaSoar]

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.

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 .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.

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 /. journal for my email should you wish to email with questions.