Confidences of the Night

Confidences of the Night is a 1975 Canadian drama film written and directed by Jean Pierre Lefebvre. The film stars Louise Cuerrier as a lonely single woman who is spending her evening at home accompanied only by the voices of other people, such as a radio phone-in show and noise from the neighbours heard through the wall; the film's limited plot unfolds when she calls the radio show to talk about leaving her abusive ex-husband, only to then receive angry phone calls from him and his mother.

Synopsis from Wikipedia, CC BY-SA 4.0. Everything below written here.