Another Woman (1988)

Marion is a woman who has learned to shield herself from her emotions. She rents an apartment to work undisturbed on her new book, but by some acoustic anomaly she can hear all that is said in the next apartment in which a psychiatrist holds his office. When she hears a young woman tell that she finds it harder and harder to bear her life, Marion starts to reflect on her own life. After a series of events she comes to understand how her unemotional attitude towards the people around her affected them and herself.

Source: TMDb