Transcript for Hearing for the First Time
word. Tonight a different kind of first, a little boy about to hear his dad's voice for the first time. This is the moment so many people are talking about, 3 years old, never heard his father before. Daddy loves you, daddy loves you. He points his finger there, hearing sound for the first time ever. Can you hear daddy? Daddy loves you. Reporter: Grayson was born without nerves in either of his ears. Watch as his father tries to talk with his little boy who in this moment was turned back to his book. Show me puppy. Reporter: Little grayson points to the puppy on that book. A moment unfolds, dad simply asks his little boy a question. Do you hear daddy? Yes? Reporter: Everyone in the room recognizing it's almost too much for this little boy to comprehend at first. It's now been a month since that moment and grayson's mother telling us she remembers it like it just happened. A mix of overwhelming joy, relief, excitement. Reporter: Without the nerves in his ears, a cochlear im plont at 18-month-old didn't work. Here's what doctors did instead. An experimental procedure, complex brain surgery, so rare he's the first child to have it in the u.S. Surgeons inserted a tiny mike chip directly in the brain stem to stimulate hearing, skipping the ears and going straight for the brain. The operation took eight hours, four weeks he would spend in the hospital sleeping with that teddy bear, grayson's mother telling us her son transformed. He's more aware of what's going on around him. Reporter: Both parents knowing the first words he heard, daddy loves you.
This transcript has been automatically generated and may not be 100% accurate.