Typically, there is a waiting period of several weeks between CI surgery and “activation,” the moment when the external equipment is hooked up and turned on for the first time. Grace’s activation date was scheduled for three weeks after her surgery, which was, at the time, a relatively short waiting period. It was expected that, as a very young child, she would heal faster than older recipients. By the day of her activation, in April of 2003, the two-inch incision that ran vertically behind Grace’s left ear was almost completely healed. It was no longer red, just a thin pink, neat scar, and the little strip of hair that they had shaved off for her surgery was beginning to grow back in a one-sided mini mohawk. In one week, Grace would be a year old.
We sat in the reception area in the main lobby, waiting for our appointment. Jill came and got us, and brought us to her office, where she explained what would happen at this visit. She showed us Grace’s hearing equipment. Her body-worn speech processor, rectangular shaped and about the size of a calculator, had a display window, buttons for power, volume, and program setting. The speech processor was the computer that would convert acoustic sound to electrical signals. Attached to the processor was a thin cable, about a foot and a half long, that ran to a small, lightweight microphone that would, with a little clear plastic hook, sit behind Grace’s ear. From the microphone, another short cable connected to the transmitter coil, about the size of a half-dollar coin, which looked a lot like a small steering wheel with a little round magnet at the center. The magnet would link to its partner, a magnet Dr. Francis had placed under the skin in Grace’s head, where the receiver would transfer the electrical signals to the surgically implanted electrode array inside of her cochlea. Which electrodes were stimulated would depend upon the specifications of the signals sent.
So, the microphone would pick up sounds, and send them to the processor, where they would be converted to electrical signals. These signals would then be sent back up the cable to the transmitter in the coil, across Grace’s skin to the receiver, and on to the electrode array. Grace’s auditory nerve would perceive these electrical signals and send them to her brain. All of this would happen in a split second.
But before we began the activation process, we brought Grace back to the sound booth for a last un-amplified audiogram. I remember thinking this was like the “before” picture, in mapped out auditory response form, for posterity’s sake. The audiogram, as always, showed a picture of what you get when you put a deaf girl in the sound booth – no response. Then we returned to Jill’s office, where we sat at the round table in the middle of the room, and armed Grace with toys. She was content, as always, to be there.
First, Jill attached the magnetic transmitter coil to Grace’s head. She linked the equipment directly to her computer, via a cord to her hard drive. She opened up the mapping program, set some preliminary parameters, and then she said she was ready to start. Grace was playing with a set of colorful wooden cars, placing them at the top of a track that zigzagged back and forth to the bottom. Her fingers were busy and her eyes followed the cars intently, as they rolled down the track. I heard the clack, clack, clack as each car reached the end of one track and dropped down to the next one. I remember thinking she couldn’t hear the cars; that she did not even know they made a sound.
And that she was completely unaware of what was about to happen.
Then, Jill sent a one-note tone directly from her computer to Grace’s CI. Suddenly, Grace turned her head and looked straight at Jill. She showed no sign of being afraid. She just seemed to know exactly who had beamed her this signal, although there were several of us in the room.
Jill smiled. “Well, that was the best response we could get,” she said. “That’s exactly what we wanted.”
Over the next fifteen or twenty minutes, Jill worked at her computer, isolating each of the 22 electrodes on the array inside of Grace’s cochlea, setting the lower and upper limits on each one. This is called “mapping”, and the process creates an individualized set of parameters for the CI user. She watched Grace carefully as she worked, looking for subtle cues in her body language as she adjusted the tones. Jill was highly experienced and had an uncanny intuition. Her job was to create a map that was loud enough to give Grace access to important sounds, especially voices, without being too loud. Jill told us, when she was finished, that she was confident she had created an excellent first-time map. Over the next month or two, Jill explained that we would switch Grace to progressively wider maps, as she adjusted to her auditory world. We spent the last part of our appointment reviewing the different aspects of the CI equipment, practicing setting it up, and asking questions.
Grace’s sensory world had changed. She had entered The Listening Center with no access to sound, and emerged less than two hours later with a whole new sense, fully awakened. In the car, she was cranky, and I worried that it was too much for her, too much stimulation, too fast. Jason smiled and said she was fine. By the time we got on the highway back to DC, Grace had conked out completely. I gently pulled the transmitter coil from her head so she could sleep in silence.