Tuesday, August 12, 2008

Left CI Activated - 8/12/2008

Early today Nichole had her new left side CI activated. Her audiologist, Marilyn, got her all hooked up to the programmer, and started out setting the T-levels (threshold levels). This is the minimum stimulation which Nichole can detect. Nichole then used the keyboard and software to set the C-levels (comfort levels) herself. This sets the stimulation level where she can hear, and it is comfortable, versus being too loud.

Once all the T and C levels were set, Marilyn turned on the microphone (after reducing the overall volume a bit to avoid Nichole being overwhelmed with sound). Nichole said that it hurt, kind of like an electric shock. Using a little electronic keyboard, Nichole played the notes, and told Marilyn exactly which notes caused discomfort, and which felt ok. Based on this information, Marilyn modified the T and C levels to a point where Nichole could hear sounds, while at the same time feel no pain. In fact, the contour of the new levels (viewed on a graph on the software) closely follow the "telemetry" readings that Marilyn took while Nichole was still on the OR table. I am not 100% sure what these are, but Marilyn said they can predict what her C-levels will probably look like after she gets acclimated to the implant. Nichole was happy with how the new levels felt.

An interesting observation was how Nichole described what she heard when she played a scale on the small electronic keyboard (left to right which would be low to high pitched notes). She said the first 6 or so keys went from high to low pitch (opposite what I hear), then the next bunch of keys went low to high (correct), then the last two were low again. I seem to recall her making the same observation at an earlier mapping session with her right CI. Not quite sure what it means though.

I asked Nichole how it sounded when we spoke (with her other CI turned off). She said that if she looks at our lips, she can make out some of the words we are saying. Wow! That is much better than when her right side was first activated a year ago. At that time, she could hear us talk, but had no idea what we were saying (we sounded like a waterfall or birds chirping). Maybe the fact that that this ear was her better ear helps. Or maybe the fact her brain has had a year with the right side CI will help it decode the new left CI. It could also be that Marilyn is using a slower stimulation rate (720Hz) which is what Nichole eventually settled on with the right side (so we wouldn't sound so "chirpy"). Most likely, it is a combination of all of the above. In any case, all the electrodes are working, and I am confident her brain will re-wire to accommodate the sounds from the new implant. I just hope it happens as quickly as it did last year (see my Day 1 Update post from last year to see how quickly she started understanding speech). She starts junior year of high school in two weeks!

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