"It was an amazing moment," said Grayson's mother, Nicole Clamp. " An overwhelming joy to see your child hear for the first time."
Grayson was born completely deaf because he lacks the nerve that sends sound from the cochlea -- part of his inner ear -- to his brain. So doctors had to bypass the body's normal hearing pathway.
A device on his ear collects and transmits sound through wires threaded through the skull. Those wires connect to an implanted electrode that sits in the area of the brain stem that processes hearing.
Head and neck surgeon Dr. Craig Buchman performed the surgery.
He responds to music and voice. I also noticed he's starting to use his voice a bit," he said.
The procedure was approved for adults in 2000. It's still experimental in children, and Grayson is among the first to receive it.
Dr. Buchman says the device may work better on younger and more adaptable brains.
"I think children present maybe a greater opportunity," he said. "We know that children's brains are much more plastic, they're able to tolerate many more things.
Nicole Clamp said it's been an emotional journey. "When you talk he looks at your mouth more and he looks more when you talk," she said. "It melts my heart to hear his voice. Any mother longs to hear a child's voice."
Doctors hope Grayson will have normal hearing, but it will take time for his brain to figure out how to interpret the new input it's receiving. As his mother told us, "he doesn't know quite yet what to do with all the sound."
The same technologies are also paving the way for other groundbreaking surgeries. For example, there's an experimental device for people who go blind; glasses that collect light waves from the outside and go right around the damaged eye directly to nerve cells in the back of the retina an on to the brain.