A deaf 3-year-old heard his dad's voice for the first time - and the world got to watch his look of delight on video. Grayson Clamp, 3, was born without the ability to hear. Thanks to a cochlear implant, he heard his dad say "Daddy loves you" for the first time.

The look of delight on his the deaf boy's face as he hears his dad's voice for the first time is priceless. And it's reminding people around the world to be grateful for an ability most people take for granted.

The cochlear implant Grayson Clamp received made him the first child in the US to receive the surgery. Previously, it was only approved for adults.

The surgery made the deaf boy able to hear by planting a microchip in his brain in an auditory brain stem transplant. It was conducted at the University of North Carolina.

Doctors aren't sure how much the deaf boy senses - but it's clear in the video that something is happening that never has happened before. We don't know exactly what it's like for him. We don't know what he hears - if he hears everything we do. His brain is still trying organize itself to use sound," Clamp's mom said.

Clamp received the transplant as part of a new Food and Drug Administration trial. The FDA is investigating the surgery. Previously, doctors had given the boy a standard cochlear implant. A device was embedded into the side of his skull.

Because Clamp was born without a cochlear nerve, the initial surgery was ineffective. The cochlear nerve helps the brain process signals the ears pick up.

Now, however, the deaf boy can hear his dad's voice - and that is life-changing.