Masking Threshold (2021) on Netflix

Plot summary

A ringing in his ears that will not stop frustrates an unnamed IT worker and data analyst. He sets out to cure the tinnitus himself. He turns his home into a makeshift laboratory and runs a series of experiments there, documenting each attempt as he goes. The people in his life reach him only as images: on his cellphone, in photographs and in printouts, among them a woman named Dana and his mother. He is a paranoid skeptic by nature, and he works alone in the lab, treating his hearing impairment as a problem he can solve through his own research.