He described numerous examples of whispering galleries.
A whispering gallery is usually constructed in the form of an ellipsoid, with an accessible point at each focus. When a visitor stands at one focus and whispers, the line of sound emanating from this focus reflects directly to the dish/focus at the other end of the room, and to the other person. Circular whispering galleries may provide "communication" from any part on the circumference to the diametrically-opposite point on the circumference.
The most famous ones in Sabine's time included:
- Statuary Hall in the United States Capitol;
- St Paul's Cathedral in London;
- The Basilica of St John Lateran, the cathedral church of Rome and the official ecclesiastical seat of the Bishop of Rome, the Pope;
- The Ear of Dionysius, an artificial limestone cave carved out of the Temenites hill in the city of Syracuse, on the island of Sicily in Italy.
[source: Spaces Speak, Are You Listening?: Experiencing Aural Architecture - by Barry Blesser, Linda-Ruth Salter]
[take a photo tour via flickr.com]