What is a Cochlear Implant?

A cochlear implant (CI) is truly a miracle.  Did you know that it is the only piece of medical technology invented so far which has been proven to restore one of the 5 senses?

A CI is different from a hearing aid, which simply amplifies incoming sound to make it loud enough for an impaired ear to hear.  Modern "digital" hearing aids have the ability to manipulate sound (called frequency "transposition" or "compression") to optimize the listening experience.  However, this is often not enough for those with severe to profound hearing loss, who may have no to few functioning inner ear hair cells left.  Unfortunately, I fall into this category.

A CI bypasses the damaged inner ear by sending electrical signals directly to the brain via the auditory (hearing) nerve. 

There are two components to a CI:

Internal (implant):  

Surgically inserted under general anaesthesia, and is responsible for delivering sound to the auditory nerve.  

I have been implanted with the HiRes 90K Implant (pictured above) with Mid-scala Electrode, from Advanced Bionics.

So, what happens during the surgery?  The surgeon makes an incision in the skin behind the ear, then drills into the mastoid bone, creating a pocket for the receiver/stimulator, and then into the inner ear, where the electrode array (the "tail") is carefully inserted into the cochlea.  

I have been able to get a copy of my surgical report from a really neat service through Sunnybrook called MyChartTM.  If you want to read it, click here.

For the masochist, here is a video of a CI implant surgery.  NOT for the faint of heart or stomach.

(P.S. - Yes, it freaks me out to know that the above is now permanently attached to my skull, but I am thinking that I will forget about it once I can talk on the phone - hopefully!).

External (speech processor):  

Worn on the outside of the ear, or sometimes clipped to a sleeve or elsewhere on the body.  

I will be receiving the brand new Naida CI Q70 processor (pictured above) from Advanced Bionics.   However, it will not be available until early summer (June or July).  Therefore, I will start out with what I will consider a "training unit", the Harmony processor, which is bigger and clunkier.

Check out all of the colours that I will be able to choose from!

As tempting as it would be to get a cute pink or a snazzy red colour, I will probably go with the "Chestnut", as this will match my existing Phonak Naida hearing aids, and will blend in with my hair.  I know.  BORING.  But, I'm a practical kind of girl.

Those who know me, know that I am a perfectionist.  It makes me happy to think that my CI and hearing aids will be exactly the same colour, and even share the same name!  

In 2009, Advanced Bionics became a sister company to Phonak, under the Sonova Group.   Leaders in hearing aid and CI technology are now joined together to form one family.  In this case, two heads are truly better than one!  And I'm the lucky recipient.

Anyway...I'm getting off track.

To help me understand how the two components of a CI system work together to help restore hearing, I found the diagram below to be helpful:

1. Sound is captured by a microphone on the external processor.
2. The processor converts the captured sound into detailed digital information.
3. The magnetic headpiece transmits the digital signals to the internal implant under the skin. 
4. The implant converts the received digital information into electrical information that travels down the electrical array (electrode) to the auditory nerve.
5. The auditory nerve sends impulses to the brain, where they are interpreted as sound.

References:

www.advancedbionics.com