Grand Central Terminal whispering gallery

The vaulted, tiled archway outside the Grand Central Oyster Bar in Grand Central Terminal produces a whispering-gallery acoustic effect where a person speaking into one corner can be heard in another. This architectural acoustic phenomenon is well-documented and demonstrated by visitors and tour guides. The idea of a 'secret' or supernatural whispering gallery is part of local lore but the effect has a physical explanation in the station's design.