From the gentle pitter-patter of raindrops on a bedroom window to the loud honking of horns in the city, noises are all around us. However, there are certain places around the world where acoustic anomalies occur that deserve a closer listen. Here are five manmade structures that demonstrate fascinating acoustic phenomena, transmitting whispers across a room or transforming sounds into unrecognizable new tones.
Hamilton Mausoleum, Hamilton, Scotland
One of the most iconic buildings in the town of Hamilton, located 15 miles southeast of Glasgow, is the Hamilton Mausoleum. But it’s what takes place inside its walls that makes it so intriguing. Built in the mid-1800s as a burial tomb for the 10th Duke of Hamilton, the 123-foot-tall Roman-style building was long billed as home of the “longest-lasting echo of any manmade structure in the world” thanks to its sheer size and shape. In fact, a single slam of its entrance door reverberates off the domed structure for a full 15 seconds. Unfortunately, it recently lost its title after a team of acoustic scientists successfully created an echo in an underground fuel depot that lasted an ear-splitting 112 seconds. But even despite thid defeat, the mausoleum still remains a popular draw and is likely one of the few places in the world where tour guides actually encourage visitors to slam doors. Listen here.
Grand Central Terminal Whispering Gallery, New York City
Throughout the day, Grand Central Terminal in Midtown Manhattan comes alive with bustling activity as commuters rush to catch their trains inside one of the city’s major transit hubs. Amid the noise, though, there’s one spot within the hundred-year-old building where it pays to be quiet. Located on the lower level near the Grand Central Oyster Bar, the “Whispering Gallery” has become a popular spot for visitors to engage in a moment of conversation that needn’t be at a shouting level. Thanks to the rotunda’s arched Guastavino tile work, two people can stand on opposite sides of the arch and, facing away from each other and towards each wall, hold a conversation at a muted tone despite being 30 feet apart. No one knows for sure if architects intentionally created the phenomenon, but it’s believed that the thin and tightly set terracotta tiles coupled with the ceiling’s curvature creates the ideal environment for this anomaly to occur. Listen here.
Temple of Heaven, Beijing, China
Built in 1420 for the Yongle Emperor of the Ming dynasty, the Temple of Heaven in Beijing is a sprawling complex that encompasses 675 acres. The grounds are home to a number of ornate buildings, including the Hall of Prayer for Good Harvests, a massive triple-gabled structure set on a multi-tiered marble base. While impressive in its own right, one aspect of the complex that causes visitors to scratch their heads in wonder is the “Echo Wall” that encircles the iconic structure. It’s believed that a number of factors are at play for creating this echoing phenomenon, including the 12-foot-tall, 213-foot diameter wall’s curvature, its tightly constructed stonework and the eaves that run along its top, making it the ideal avenue for the transmission of sounds between two points along the wall. Listen here.
Whispering Gallery, National Statuary Hall, U.S. Capitol, Washington, D.C.
There are a number of rotundas around the world where similar acoustic anomalies occur, including the Texas Capitol—but perhaps the most heavily trafficked one is the Whispering Gallery located inside the National Statuary Hall, a chamber within the U.S. Capitol. For years, echoes had been the bane of the Greek Revival structure’s existence due, in large part, to its tile floor and domed shape, which together helped to carry sounds throughout the chamber with little interruption. Although beautifully designed, it was problematic as it was frequently too loud for politicians to hold debates. Thus, over time, curtains and statuary were added to the interior. Despite this, one acoustic phenomenon still remains: if you stand directly in the center of the room while another person stands in the periphery, you can clearly hear his or her voice. Listen here.
El Castillo, Chichen Itza, Yucatan, Mexico
Perhaps among the strangest sound anomalies in the world is the one heard at El Castillo, also known as the Temple of Kukulcan, located in Chichen Itza, a city within the Yucatán state of Mexico. Built by the Maya civilization sometime between the 9th and 12th centuries, the ancient Mesoamerican step pyramid is part of a larger complex that includes a ball court, temples and various other buildings. While archaeologists are continually learning more about the complex and the Maya people every day, one aspect that remains a mystery is the strange sound that occurs when you clap your hands. All you have to do is stand in the field facing the exterior steps of El Castillo and do a single clap and you’ll immediately hear an echo that sounds eerily similar to a bird chirp. Listen here.