Airport noise could be significantly reduced through the use of novel landscaping. The geometric designs, aimed at reducing the rumble of massive jet aircraft, resemble soundproofing materials used in recording studios.
Not only could these designs reduce noise, but they can also provide a play space for visitors.
Schiphol Airport outside Amsterdam has already installed some of the geometric designs, in an effort to reduce the often-dangerous levels of noise emanating from the highly-trafficked airport.
High levels of noise are linked not just to hearing loss, but also heart disease, which can potentially be fatal. As cities expand, greater numbers of people are starting to move near airports, which can present hazards to those living within flight paths.
Ridges in the dual-purpose parks reflect and absorb engine sounds, reducing noise pollution by half for people living in areas surrounding the airport.
The area surrounding Schiphol Airport is extremely flat, allowing noise from jets to race across the landscape nearly unhindered. A large flat barrier, such as a wall, would be unable to stop many low-frequency sounds. However, airport officials noticed that noise levels dropped slightly during autumn, when agricultural fields near runways were plowed, producing furrows and ridges. After testing artificial ridges, officials there decided to build permanent, larger versions of the features.
At Schiphol, the 150 ridges used in the construction of the noise barriers are roughly 10 feet tall, 36 feet wide, and 150 feet long. People can walk between the structures, allowing for recreation while reducing noise from aircraft.
"Originally, the ridges would have been very long and straight and dull. By making this pattern, there's a lot of corners and little open spaces. So it's a prettier landscape," said Paul de Kort, a land artist who worked with H.N.S. Landscape Architects to create the design.
The ridge patterns used at Schiphol were inspired by Ernst Chladni, an 18th century artist who made sound visible by running a violin bow over a metal tray filled with salt or sand. Doing so created ripples, such as those seen on a still pond.
A small diamond-shaped pond is also included in the network of sound barriers. Visitors passing over a bridge crossing the water body are able to create ripples in the pond.
"In 1998, the Dutch government imposed a noise pollution limit, or noise budget on Amsterdam's Schiphol Airport. The limit was based on a total annual noise budget that allowed 380,000 flights in 1998, with allowable increases of 20,000 per year for five years, provided that there is no change in the noise contours," NASA reported.
Gatwick Airport outside London and the airport in Melborne, Australia are already starting to experiment with similar landscaping ideas to help reduce noise at those facilities.