The actor, who plays a drummer battling the loss of his hearing in the movie, is an early Oscars favorite for Best Actor but his reward for making the film came as he wrapped the project.
"This film was really the most challenging, the most immersive, the most intense experience of my life and the day we finished I told our director, Darius, if no one sees this film I'm still happy, because it just kind of changed me; it changed all of us...," Riz tells "Good Morning America". "It was a labor of love."
"It kinda changed the way I look at life, spending so much time with the deaf community, learning [to play] the drums, it opened me up in new ways."
"The fact that people are seeing it, let alone responding to it like this, is just the most mind-blowing bonus."
And the film made him a better listener, even though he was playing a deaf person.
"My sign instructor... and the whole deaf community that he introduced me to in New York, I kind of think that they're the best listeners I've ever met, because listening isn't something you just do with your ears; it's something you do with your whole body..."
"On the film set, I was using audio blockers at times for when my character starts to lose his hearing - just to simulate that experience - and it made me listen with my body... The deaf community taught me the true meaning of listening, the true meaning of communication."