I took today off from work so I could drive Rebecca to the audiology office and be with her when they activated her cochlear implant. Rebecca's mother Ann is in town to watch the girls.
The morning was mostly normal. Rebecca wanted this day well-documented, so I spent some time taking videos with the camera (with Ann's help) of everyone getting ready. We all had a nice breakfast together then Rebecca and I drove to the office.
We waited only a minute or two before Amy, Rebecca's audiologist, welcomed us in and led us back to a room. She had some cables connected to a notebook computer and an assistant, Ashton, who will be receiving her Ph.D. in May.
Rebecca sat next to the computer and Amy and Ashton started putting various implant pieces together. Part of the processor is held on to Rebecca's head with a magnet, and it took them a few tries to pick a magnet that was strong enough to hold on but not so strong that it would give Rebecca a sore on her scalp. They settled on a "number 4" magnet, whatever that means.
The part of the implant that is inside Rebecca's cochlea contains a series of electrodes that stimulate different parts of the auditory nerve. Stimulation in different parts of the cochlea is what makes sounds different. An electrical impulse in one part of the cochlea is interpreted by your brain as one sound, and an impulse in another part of the cochlea is interpreted as a different sound.
The first tests Amy did involved activating one electrode at a time and sending electrical impulses, starting very weak and gradually building up until Rebecca either heard or felt something. The processor would send a series of pulses to the implant, and if Rebecca did not hear anything or could not determine how many impulses were sent (between 1 and 5), Ashton (who was working the computer) increased the power.
This process was repeated for each electrode (I think there are 22). Rebecca described the sounds she was hearing as low bells ringing, with lots of reverberation.
After Amy was satisfied with the power levels on each of the electrodes, she turned them all on at once, at a very low volume. The entire process is quite gradual, but if we had to point to a moment and say, "This is when we threw the switch,"this is that moment.
With the implant on, Amy started to talk to Rebecca. At first, she said she only head the bell sounds, one on each syllable that Amy spoke. But after a surprisingly short time, Rebecca started to recognize Amy's voice. "I can hear you!" Rebecca said, holding back her tears. It was moving and incredible touching.
Hopefully the above explanation will help you understand what is going on in this video:
Cochlear Implant Activation from William Jackson on Vimeo.
The processor (the device you see behind Rebecca's ear) contains the microphones that pick up sound. It converts those sounds to electrical impulses that are sent through the headpiece (the round thing that holds to the side of Rebecca's head with a magnet) to the implant inside Rebecca's head. All the external parts can be turned off, and when they are Rebecca won't hear anything in her right ear. So if she wants it to be quiet, she can make it quiet.