Tiny Pianos

Most of our senses are ‘mapped’. That is, a particular location in a sense organ stimulates a corresponding point in our brain and adjacent sense locations stimulate somewhat adjacent points in the brain. For example: sight, taste, touch.

Hearing is similar in that each location in the cochlea maps to a particular frequency or pitch. The base of the cochlea is mapped to low frequencies and the tip or apex maps to high frequencies. Something like a tiny piano keyboard rolled up into the size of a pea. This ‘piano’ normally has about 1,500 different ‘keys’.

The cochlear implant, by comparison, has a mere 16 keys. Ideally, those 16 keys would take the place of the normal 1,500 keys. In fact, that isn’t going to happen. The external electronics will be programmed to squeeze the incoming sounds into 16 bands. My brain will have to figure the rest out. It won’t be perfect but, chances are, it will be better than what I have today.

In addition, the electronics will also have to be programmed to accept sounds at all sorts of intensities and convert them in to electrical impulses that are somewhere between barely detectable and fuse-blowingly loud. Again, my mind will have to figure out just what that means. Is that noise a mosquito or a helicopter?

This learning process will begin at the ‘turn on’ date which is next Friday (Jan 30th) and it will continue for a while. I have appointments for mapping adjustments at Sunnybrook all the way until January 2011!

I’m told that one of the best ways to train the brain to make sense of the cochlea implant signals is to listen to an audio book while following the corresponding text on paper or on a computer screen. There’s a lot of stuff floating around on the web that can help and I’ve been checking out some of this today. For example, Project Gutenberg has loads of stuff. The nice thing about some of this is that the voices sound fairly normal (well, to me at any rate). Some commercial audio books I’ve listened to in the past are overly theatrical and have music added into the background. That’s OK for some but it’s not what I want for this purpose.