Mysterious bell ringing in NY subway station stairway at 50th Street for weeks, source unknown.

A mysterious bell has been ringing in a NY subway station's stairway to the downtown 1 train platform at the 50th Street station for weeks. The source of the noise remains unknown, with no visible bell in the area and its volume fluctuating throughout the tunnel. Store owner Adrien Gallo experiences the bell's sound more strongly in certain locations and has to endure it all day at work.