Cochlear Implants

After a week of being an invalid, I am feeling much better this weekend. My ear is still a bit sore and somehow I don't feel as well glued together as I would like, but I am up and able to cook, read and write.

On Tuesday, I have an MRI scan to check that the implant is in the right place. Not sure what happens if it isn't. Then on Wednesday, I meet the consultant surgeon who will check he is happy with healing and other developments. Hopefully, the dressing comes off soon afterwards and I am back to work a week tomorrow. Thank you, by the way, for all the good wishes both here and through other mediums.

The implant gets turned on in three weeks time, all being well. It has, if I recall, twelve electrodes that are threaded through my inner ear. These should be able to stimulate the aural nerve that previously carried signals from the hair cells in the cochlear. These hair cells vibrate at different sound frequencies, sending messages to the brain as they do so. Sadly, mine have been dying off at an accelerating rate, starting at the outer mouth of the cochlear (the high frequencies) and working inwards. I now have natural hearing only at the very lowest frequencies, the hair cells for which are at the centre of the cochlear. The implant will have destroyed any remnant of natural hearing on my left hand side, so I am currently existing on one dodgy ear.

The implant is controlled by a processor that lodges behind the ear and looks like a super-sized hearing aid. This has a microphone on it to pick up sound. These sounds are converted into very small electrical impulses that are sent down to the implant itself. The implant is completely internal and the signals have to be sent through the skin via a special magnetic disc. The twelve electrodes in the implant should each be keyed to particular sound frequencies. They stimulate the nerve-endings close to them which send signals to the hearing centre in the brain. The signals initially don't bear much resemblance to what the brain is used to so it must reprogram itself to cope with the new information. This can happen very quickly or take a while. I will be interested to see what 'sound' sounds like through the implant and how quickly my brain can piece it back together again.

Some more news next week.

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