Noise — Ending Explained

As Joo-young digs deeper into Samil Apartments with Ki-hoon, she uncovers the dark reality of the building and unit 604:

• The Red Herring: Geun-bae (unit 504), despite his violent demeanor and terrifying threats, is not the killer; he is merely an equally broken victim who is losing his mind due to the actual noise.
• The Conspiracy of Silence: The homeowners' association, led by the chairwoman, actively covered up previous deaths, mental breakdowns, and a string of illegal incidents in the building to ensure municipal clearance for their lucrative reconstruction plan.
• The Origin of the Malice: The noises originate from unit 804, where an earlier resident died under horrific, unresolved circumstances, leaving behind an entity of lingering resentment (han) that feeds upon the frustration and anger of the tenants.
• Joo-hee’s Fate: Joo-young ventures into the sealed, trash-choked bowels of the building's utility corridors and basement. She discovers that Joo-hee did not simply run away; she was trapped, assaulted, and killed by the malevolent presence/deranged occupant stalking the upper floors.
• The Climax & Ending: Confronted by the murderous woman/entity of unit 804, Joo-young uses sign language and tactical silence to navigate the corridors and outsmart the attacker, who hunts purely by sound. In the climactic struggle, Joo-young turns off her hearing aid, cutting off the sensory vector through which the ghost torments its victims, and manages to survive. However, the film closes on a haunting, melancholic note: as Joo-young leaves the complex, she realizes that while she survived the physical encounter, the phantom whisper of her sister will forever linger in her internal silence.

Viewers and critics have proposed several alternative readings of the narrative:

• The Supernatural Grudge vs. Collective Mass Psychosis: While the film features ghostly manifestations and malevolent entities, a strong psychological reading argues that the "noise" is an auditory manifestation of shared mass hysteria, insomnia, and the corrosive guilt the characters harbor.
• Auditory Hallucination of Guilt: Some critics interpret the entirety of Joo-young’s encounters with Joo-hee’s presence as an externalized manifestation of her survivor's guilt. Because she was absent when her sister needed her most, her mind constructs a phantom investigation to process the tragedy.
• Ambiguous Reality of the Final Scene: The open-ended finale leaves viewers questioning whether Joo-young truly escaped the building's grasp or remains trapped in an eternal acoustic loop alongside the spirit of her sister.