Video: Deaf three-year-old boy hears for the first time
Deaf three-year-old Grayson hears his father's voice for the first time after surgery in the US.
Grayson was born deaf, but a successful surgery at the university of North Carolina means he can now hear.
The toddler received an brain stem implant as part of a trial at the hospital.
They were testing to see if the implants could work for children, as they are already used on adults.
Doctors used the type of hearing implant that was directly placed on his brain stem.
Grayson is the first child in the US to receive the brain implant, and will now have several years of therapy to improve his hearing and speech.