The whispering arch is a treat, talk towards the wall and someone 20 yards away can plainly hear you. pretty cool.Aquariuz, Trip Advisor
The whispering arch is the structure to the left in the old postcard, there’s a plaque marking the spot. This whispering arch dates back to when the building was a large railway station in the nineteenth century. When someone talks into the wall, you can get sound that stays close to the edge of the arched ceiling. A classic way of illustrating this is to consider sound as a snooker ball bouncing around the edge of a circular table.
In the lobby of the St. Louis Union Station Hotel. Head for the stained Tiffany glass window featuring three robed women figures.
Photos: Public Domain and onasill