A 3-year-old boy is hearing the world for the first time, thanks to an auditory brain stem implant.
"He likes sound," young Grayson's mom Nicole Clamp, said to CBS affiliate WBTV in Charlotte, N.C. "He enjoys the stimulus, the input. He's curious, and he definitely enjoys it."
Grayson Clamp was born without his cochlear nerves, or the auditory nerve that carries the sound signal from the cochlea in the inner ear to the brain. His parents tried giving him a cochlear implant, but it did not work.
They then enrolled Grayson in a research trial at University of North Carolina Hospitals in Chapel Hill, N.C. Three weeks ago, he became the first child in the U.S. to receive an auditory brain stem implant.
The procedure involves placing a microchip on the brain stem to bypass the cochlear nerves altogether. The person perceives and processes sound, which travel through tubes in his ear.
Dr. Craig Buchman, Grayson's head and neck surgeon at UNC, explained to CBSNews.com that the devices were made several years ago for adults who have tumors in their cochlear nerves, but it has never been approved for use in children in the United States.. While the implants were able to give back some hearing to the adults that received them, they were not as effective as cochlear implants.
However, Buchman's team's theory was that if the auditory brain stem implant was put in a young child, they may be better at processing the sounds.
"One of the reasons we really were interested in this study, children have enormous potential because of their brain plasticity," he said. "They have enormous potential to interpret sounds.... I don't know what he hears and how he's going to use it, but only time will tell."
Grayson was the first chosen because he had high cognitive abilities and used cued speech, a visual system based on phonetics used to communicate. That way, doctors could see if he was hearing anything and responding to sound stimuli.
When he heard his father calling him for the first time, his face lit up with shock. Buchman said he was pleased with Grayson's responses.
The child still has to go in for frequent checkups to fine tune the device in order to give him the best hearing possible.
"We don't know exactly what it's like for him," Nicole explained. "We don't know exactly what he hears. His brain is still trying organize itself to use sound."
In total, Buchman's team has evaluated 10 children who all have similar problems with missing nerves. Right now, they're limiting the study to younger children who don't have that many additional health or cognitive issues to see what the potential of the device is. If they are successful, they are hoping that older children who haven't learned how to speak because of their hearing problems may be given a chance to finally hear and talk.
As for Grayson, he's already benefiting from his new hearing abilities.
"It's been phenomenal for us," his father Len Clamp said to WBTV.