Over 1.2 million people have now watched the YouTube clip of the moment 15-year-old Patrick Otema communicates using sign language for the first time. His smile has moved people to tears and inspired many to get in touch with us to find out how they can support projects like this one.
Neither director Daniel Bogado or I could have ever imagined we would witness such a pure moment of sudden realisation and transformation when we set out for Uganda to make this Unreported World documentary for Channel 4.
Patrick and his father live in Agago in northern Uganda, an area previously ravaged by the Lord's Resistance Army. The memory of war hangs heavy here; walls pockmarked by bullets, families disjointed with too many fathers, sons, mothers and sisters gone. Patrick was born in a camp for internally displaced people. Here, being deaf is another kind of incarceration. With no deaf schools in the entire province, Patrick missed out on any kind of education and could only communicate with his father using very basic gestures.
We filmed Patrick attend his first ever sign language class, and witnessed him realising he is not alone - and that there is a language for people like him.
He is now being taught by Raymond Okkelo, a 23-year-old who only learnt sign language six months before on an intensive programme created by the Ugandan National Deaf Association. Those first students have now all returned to their villages to teach others. Raymond's class started early - people just started turning up - and it went on long after it was scheduled to end. Family members joined in and there were even a few nurses and a police officer in the class, all determined to learn to communicate with deaf people in their community.
We also spent a lot of time filming at the Kinyinya Deaf Unit primary school in Western Uganda. Here, I asked students what their lives were like before they could communicate using sign language.
"Before, I was alone and scared," said Jacklin Mukamungu, a 16-year-old who has spent most of her life living in a refugee camp near the border with Rwanda. "Now, I feel free, I am happy. I am proud."
Her description of life 'before' sign language and 'after' was repeated to us time and again by her school friends. Although they now communicate fluently in sign language, their descriptions of what they felt before they could sign were limited: they all described their old existence as unhappy.
This is the reality for most deaf people in sub-Saharan Africa, where most never learn sign language. In Uganda, there is roughly double the number of deaf people as there are in the United Kingdom because many become deaf as a result of diseases like malaria, measles, mumps, meningitis or being born to mothers who contracted rubella during pregnancy.
I could not stop thinking how in the rich north, these diseases are easily preventable with routine vaccinations. I also could not stop thinking about the incredible, moving videos we now regularly see in the wealthy parts of the world of people being fitted with cochlear implants and hearing sound for the first time.
Mistakenly, these videos make many think that deafness is on the wane. Far from it. Cochlear implants are not appropriate for every deaf person for whom they are available; for many they just don't work. And considering they cost the NHS about £40,000 to fit per implant, they are absolutely unheard of in places like rural Uganda.
Cochlear implants are controversial in the deaf community, I have learned since starting work on this documentary. Many quite rightfully reject the idea that their deafness is a problem which needs rectifying through surgery when sign language provides a full and rich linguistic culture for all those who use it. Meeting deaf people in Uganda working hard to help others gave me a privileged glimpse of this culture for the first time.
Everyone has the right to be able to communicate, to have a voice and to be heard. For millions of people like Patrick, the answer lies in sign language.