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Cochlear Implants FAQ

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Introduction

Cochlear implants are one of the subjects which rouse controversy in the world of the deaf and those professionals who attend to the needs of the deaf.

It is claimed by some that people who are considering cochlear implants for their children or for themselves are not sufficiently informed about the risks and consequences of making the decision to undergo the procedure.

The purpose of this part of the DEAF-INFO Web Site is to make information and opinions about cochlear implants available and easily accessible on the Internet.

I wish to give a big bag of thanks to Miriam Clifford for the effort which she put in criticizing this document and suggesting various modifications, even though I decided not to implement most of her suggestions.

If you believe that this part of the DEAF-INFO Web Site does not make a balanced presentation of the facts and opinions about cochlear implants, please E-mail your comments to me. Don't forget to write up your suggested modification or addendum to the FAQ. I will probably reject suggestions to delete parts of the FAQ. But I will probably accept suggestions to add more arguments in favor or against any point made in the FAQ.

Analysis of potential physical hazards

Question:
Is there risk from strong magnetic fields to people who have been implanted?

Answer from a physicist:
(Contributed by Bill Peter at 8 Dec 1993.)

Since you still insist on my *proving* to you that that magnetic fields can't hurt cochlear implants, let me outline my proof: it is simply an antenna problem. Take the wave equation and couple it into a small wire that we can model as the implant (length of, say, 2*pi*3 cm; zero width). Now we know that 3 cm corresponds to about 10 GHz, so for this problem we have about 2 GHz (around microwave C-band). Even assuming a nuclear blast or some kind of large EMP, the frequencies are somewhat limited. To get an idea of the magnitude of fields required to even heat the implant, calculate the induced current on the wire from a large magnetic field, we're talking about fields way in excess of 10 KG! To calculate this consider a simple loop of (say) 3 cm. The area is about 30 cm~2. By Faraday's law of induction, depending on the loop resistance, we can solve for the current, and from that the Joule heating...in sum, NO PROBLEM... [don't forget to include in d(BA)/dt the fact that dB/dt ~ 2*pi*f*B].

And now answers from other people, which contradict the above:

(The following, dated 10 May 1995, is from:
Leon A. Metlay, M.D.
Associate Professor of Pathology and Laboratory Medicine
University of Rochester Medical Center
P.O. Box 626
Rochester, NY 14642

Phone: (716) 275-5691
Fax: (716) 273-1027

WWW Home page: http://wwwminer.lib.rochester.edu/wwwml/Leon/URPLM.html.)

I talked to a neuroradiologist (they are the people who actually do head MRI scans). He said that the magnet of the MRI might indeed ruin the mechanism of the CI. He gave me a long list of things which can be implanted in people's ears and whether or not they are safe for MRI:

  • All models of CI are NOT safe for MRI.
  • Magee piston stapes prosthesis is NOT safe for MRI.
  • A long list of other prostheses ARE safe for MRI.

The list changes from time to time, so if you have an appliance in your ear, consult the Radiologist before having an MRI. This includes having an MRI on some other part of your body, because there is high likelihood you'll have to put your head near the big magnet even if you're getting an MRI of your foot.

(The following, dated 19 May 1995, is from Paula Tucker.)

I attended the NIH Concensus Conference on Cochlear Implants, and one of the sessions was about CIs and MRIs. In fact, in an MRI, the implant WOULD heat up, as well as be dislocated. Since the chance of a young person needing an MRI sometime in his or her life is now approaching 100%, it is indeed a concern.

However, new materials are being developed so that most likely one day this will no longer be a reason not to have an implant.

Update as of January 2006

Some CI manufacturers now rate their CIs as safe for use in MRI scans with magnetic fields whose strength is 1.5 tesla or less.

Cochlear implants in various countries

See Cochlear Implants FAQ - Country Information
Australia
Brazil
Canada
France
Great Britain
Israel
Norway

Informed consent - fact or myth?

Robert Pollard, Ph.D. statement from 17 Nov 1993:

The significance of the medical community as a pwowerful and early influence on families with deaf children should not be underestimated. It is not the same as your comparison of Black families, etc. Indeed, quality of life research and academic discussions ARE a very important part of the medical literature in such conditions as diabetes (as you brought up), seizure disorders, etc. There IS a proper place in the medical literature for looking at the whole individual even when the individual otherwise has a "medical" issue of importantce to the physician. A wider view of the possibiltieis, potentials, resources available to deaf individuals is part of the doctrine of informed consent and helping patients have informed consent when they discuss medical or even educational interventions. Many physicians lack this information themselves and the NEJM is an excellent place to begin to expand this kind of knowledge.

Reggie [email protected] statement from 15 Nov 1993:

I am a Deaf history buff. During my research, I have not yet seen such argument that inferred Deaf people were against hearing aids. It is possible that I overlook this, but most of my findings mentioned that the Deaf community was not against the hearing aids itself, but aganist the people who tried to sell hearing aids. One of the tactics they used to convince people were that they helped the deaf children to speak better, to hear perfectly and to improve on their reading and writing skills, etc. Here is one of the most drastic examples: In 1950's, a group of hearing aid manufacturers and speech and hearing pathologists tried to get a bill passed in the Pennsylvania Legistative to became a state law. The bill proposed that Deaf persons would be required to have hearing aids if they wanted to drive a car. Fortunately, this bill was thrown out. If it had been passed, the hearing aid manfacturers and audiologists would have profited from the law.

In general, the Deaf community is not against cochlear implants also. The hearing aid salesmanship ploy somewhat parallels with the manipulation of selling the CI idea to parents of Deaf children. For instance, the FCC permits 2 years old children to have CI implanted. This is the reason why the Deaf community is againist it for the children are not old enough to have a decision about wearing CI. The Deaf community also resents some of the arguments that the CI advocates stated. One example is that the CI advocates implied that the Deaf community are afraid the CI will cause their culture to diminished. It is untrue.

Cathy Brandt statement from 6 Jan 1994:

From my limited eperience with cochlear implant teams - one from Shea Clinic and the one here at the University of Kentucky - they say that children who attend signing deaf schools are typically NOT the best candidates for an implant due to the lack of auditory input that is provided.

The phenomenon of the Deaf adolescents, who actively decide to stop using an implant put in when they were 10, has happened in some children I know. I wonder how how much of it is due to typical teenage type emotions, reactions etc.

Also, kids who were implanted at 10 have VERY different experiences and ability of use than kids who were implanted from age 3 to 7. My oldest was 10 and the difference between her and the kids who were implanted at a younger age is extraordinary. However, I do have another student who was implanted at 10 and is doing extremely well in the six short months she has had it. However, she has had some problems with the skin/incision healing properly. But, she still WANTS to use the implant.

Here in Lexington part of the cochlear implant team are teachers and pathologists who do know quite a bit of sign language and work with children who sign on a daily basis. They are a part of the educational part of the team - not the medical side of the team.

But, I agree they are not always given the OTHER side. I do think CI's are often pushed in some instances when it may NOT be in the best interest of the child.

A sensible family's attitude toward CI

On 5 Mar 1995, Claire Lynn Wells posted to DEAF-L an account about two families, which have sensible attitudes toward CI's:

"... BTW, both these families I mentioned still sign to their kids. They see a CI as a way for them to develop auditory, speech, and speechreading skills in addition to their language/sign skills.

"I watched a video of one of the children of the mother from Kansas, before and 3/4 years after, and I just couldn't believe the improvement in her speech. But will speech replace sign as her primary means of communication? We'll see. It doesn't matter to her mom either way. And yes, she knows ASL, too."

Those families consider the CI as the cure all for deafness, but only as another means for improving the quality of life of deaf children. They accept the fact that their children are and will continue to be deaf in spite of the CI.

This kind of attitude serves to reduce the psychological risk of implanting deaf children.

Warning: false claims about CI in ads

There was a report that one of the CI manufacturers places in some newspapers ads, which are blatantly unbalanced pro-CI propaganda. Those ads do not appear in newspapers in USA, but in some Pacific Rim countries.

Those ads, if they indeed exist, may have the following undesirable consequences:

  1. People - both deaf and hearing - may get the false impression that CIs are magical cure to deafness.
  2. An adult deaf person (probably late-deafened) who applies for CI and found to be unsuitable for this due to medical reasons - may be so fixated on CIs that doctors, hospitals and CI manufacturers who are slightly pressed for money - would find it difficult to turn him down.
  3. Even if someone has a realistic attitude toward CIs and decided that they won't benefit him, he may be subjected to peer-pressure to continually justify his decision to continue to lead the life of deaf without trying CI. If he breaks down and does try CI, it would solve the peer-pressure problem but he will have been subjected to a big expense (both monetary and in invested time).

In effect, those CI ads promise to hearing people:

"Nag your deaf acquaintance to have CI and then you'll not have to speak clarly to him, update him about the going on in a group conversation, hold phone calls for him, pay for his interpreter". This is incorrect in large percentage of cases.

See also The Cult of the Holy Cochlear Implant.

What to do about those ads?

I suggest that some smart lawyer/s in those pacific rim countries would find a way to cause the cochlear implant companies to be liable for any adverse results due to peer pressure induced by their ads.

In other words, suppose that:

  1. Someone got deafened.
  2. He was evaluated and found to be medically insuitable for CI.
  3. He was subjected to peer pressure.
  4. He submitted to CI operation.

Then he should be able to sue the cochlear implant company, hospital and/or surgeon if the CI failed to perform according to the unrealistically high expectations of his peers - who were influenced by the ads.

Last update date: 
2006 Jul 17