Little Grayson Clamp is three years old, but he just heard his dad's voice for the first time three weeks ago.

The North Carolina toddler was born without a cochlear nerve — the bridge between the auditory portion of the inner ear and the brain — but a cochlear implant, which has worked wonders for others, did nothing for him.

That's when Grayson's adoptive parents, Len and Nicole, decided to enroll him in an ongoing FDA trial for a new kind of "miracle device" known as an "auditory brain stem implant."

Grayson is the first child in America to be implanted with the microchip, which aims to act as a substitute for the missing nerve.

In recently released video from the University of North Carolina School of Medicine, Grayson can be seen "lighting up" to the sound of his father saying "daddy loves you."

"It's been phenomenal for us," said Len.

Nicole noted that they still have much work ahead of them teaching their son how to process his newly acquired sense.

[H/T: HyperVocal]