Unrecorded Echo

In order to save money, Jiang Yan rented an old building with mottled gray walls in the old city. On the first day after moving in, Jiang Yan was quite satisfied with the silence of the corridor. He subconsciously believed that the sound insulation was good and could avoid neighborhood disputes, so he didn't notice anything strange at all. This dilapidated old building has no good sound insulation. It is obvious that there are few residents in the building and there is no atmosphere of life. It is as quiet as a dead city.