Nightly News | June 20, 2013
>>> finally tonight, perhaps it was forwarded to your inbox today, the piece of video on the web, where the sound you hear is the most crucial thing. it shows a little boy , hearing his father's voice for the first time and it represents an even larger story of the great science that made it possible. our report tonight from kate snow .
>> reporter: 3-year-old gray son clamp back at his doctor's office today for a checkup. he was born with a host of medical issues, open heart surgery as an infant, vision loss in one eye and no auditory nerves in either ear. but about four weeks ago after ground-breaking surgery. little grayson heard his daddy's voice for the first time.
>> daddy loves you, daddy loves you.
>> yes. hear.
>> can you hear daddy?
>> mom niccole shooting the video.
>> when they turned that thing on and it worked, the weight was lifted off me. a long road getting there.
>> reporter: niccole and lynn are high school sweethearts, who adopted grayson out of foster care .
>> he is a really smart little kid, and he wants to tell us a lot.
>> i can hear myself.
>> reporter: the viral videos of the indescribable moment when a person hears for the first time. but this is a milestone. grayson 's implant requires brain surgery and first child to receive one as part of an fda-approved trial. the whole family's world has been turned upside down. mom niccole hopes he starts using words.
>> my dream, he will develop intelligible speech and he is able to function independently. anything that any mom wants for their little boy .
>> reporter: they hope that other families get to experience the same joy. kate snow , nbc news, new york.