Because the main character is deaf and mute, the film contains less than 15 minutes of dialogue, meaning that more than 70 minutes occur without a single word spoken.
Director Mike Flanagan didn't want the film to be pure silence, so he added various ambient sounds such as an ultrasound machine.
Director Mike Flanagan and co-writer/star Kate Siegel are a married couple, and conceived the storyline for Il terrore del silenzio (2016) while on a dinner date in 2014. They wed in February, 2016.
The blurb on the back of the book Maddie wrote (Midnight Mass) references some details of the later Netflix series "Midnight Mass" (2021, also by director Mike Flanagan). The main location, isolated Crockett Island (spelt here as Crocket Island), main protagonist Riley and a church are mentioned. The main female protagonist of the series, Erin is mentioned by Sarah along with Riley.
Filmed in 18 days.