An unbearable noise from neighbor invading private life and personal space brings chaotic madness and psyche. Joo-young is a hearing-impaired woman relying on a hearing aid. Shortly after she moves to a new apartment, her sister goes missing. While following the leads, she finds out her sister's disappearance may be related to mysterious noises heard in her apartment. Questioning suspicious neighbors and tracking the source of the noise, Joo-young starts to experience strange and horrifying incidents around herself.