In the wake of World War I, the United Kingdom developed a powerful yet relatively low-tech architectural system for detecting incoming enemy airplanes, the remnants of which can still be found across the countryside.

Starting in the 1920s, these concrete sound mirrors were built to passively gather, reflect and concentrate acoustic waves, directing the sound to listening posts on the ground — key infrastructure in an extensive early warning alert system.

Incoming sounds were amplified by microphones and listened to by operators wearing headphones. Today, the remains of these mirrors are largely abandoned and in various states of disrepair, though some are protected with walls or fences and accompanied by historical plaques.

Based in Basel, photographer Piercarlo Quecchia discovered the existence of sound mirrors thanks to an album cover featuring one such structure. From there, he began the search out, find and photograph them — 13 in total (all that remain), most of which are located along the southern edge of England.

They may look monolithic and simple, but the curves of these structures were carefully calibrated. The designs were specifically calculated (and sound mirrors accordingly engineered) to pick up aircraft engine noises in particular.

“They represent an incredible demonstration of how sound can generate a physical form,” explains the photographer, in which “both the curvature radius and the dimensions of the dishes are studied and designed according to the sound frequency that they must reflect,”  He hopes the series will continue to raise awareness of these artifacts and bolster preservation efforts.

Like the airmail arrows that once guided planes from coast to coast across the United States, it can be easy to overlook such geometrically simple leftovers, at least until an understanding of their historical origins leads people to spot and appreciate them.

Between fireworks and thunder, it can be hard to watch your best friend cower and howl when noises beyond your control dominate the soundscape. This noise-cancelling kennel aims to provide shelter from auditory storms, an more robust alternative to hiding in the closet.

Developed by Ford Europe, the structure employs a combination of sound insulation and, critically, the technology used for noise-cancellation in the company’s automobiles.

Adapted to frequencies that most impact canine companions, microphones pick up the sounds of explosions and other loud bursts, then counteracts them with mitigating frequencies.

A combination of soundproof ventilation, acoustic isolation panels and speakers alter the incoming soundscape to create a refuge, all packaged within an angular minimalist kennel frame.

This 230-foot-long musical instrument contains 35 organ pipes and is powered by the Adriatic Sea, producing sounds for visitors that seem eerily composed rather than random.

Whistle holes cut into the stone steps are ‘powered’ by air pushed in by waves of water, creating chords that are strikingly harmonious in nature. The sounds are constantly shifting, but you can listen to a clip above (a .wav file of the waves, if you will).

The Sea Organ, or the Morske Orgulje, is part of plan to revive Zadar, a city over 3,000 years old that was nearly obliterated in the Second World War. Architect Nikola Baši? wanted to give the place something with character, differentiated from the stark and boring concrete buildings that were created during initial years of rebuilding.

The design was inspired by the Hydraulis, an ancient Greek instrument that used water to push air through tuned pipes, but also borrows from the Wave Organ in San Francisco, a likewise seaside device amplifying the sounds of the Pacific Ocean. (images by linssimato, Lisa and J We).

Lighting up streets and sidewalks of Rio de Janeiro, these mobile animation units utilize the movement of tricycles and available city surfaces to create amazing and interactive works of art.

The so-called Suaveciclos were designed by artists Ygor Marotta and Ceci Soloaga of VJ Suave from São Paulo, combining batteries, laptops, projectors and speakers to create a multimedia experience.

While some of the works are projected up high, those aimed at human-accessible surfaces (roads, sidewalks or low walls) are remarkably engaging, sparking children to start playing with the live projections.

The versatility of these stop-and-go projection systems (tweakable to context) make it easy for the artists to react to crowds, stopping where popular or pressing on when their work at one site has run its course. They have pedaled their act in cities in Russia, Luxembourg, Slovakia Germany and Switzerland as well.

From the artists: “small narratives with characters and poetry can travel open spaces, lighting walls on a large scale. The projections illuminate walls, trees, lakes, sidewalks and propose a playful interactivity with the public. With the video manipulated in real time, Suaveciclos bring art to all audiences and create unique moments between the city and the viewer.
In their playful universe, vjsuave deals with current themes with ambient sound accompanying the performance” (h/t Colossal and  Prosthetic Knowledge).

Large enough for visitors to enter and sit within, three gigantic wooden megaphones constructed in the forests of Estonia amplify ambient sounds of the environment.

Nearly ten feet in diameter each, huge cones render quiet sounds of rustling leaves and birds chirping remarkably audible.

The Tõnu Tunnel installation was conceived of by interior architecture and design students from the Estonian Academy of Arts and implemented with advice from B210 Architects

Thanks to their size and shape, the megaphones double as seating and shelter as well with space enough for a few hikers to spend the night.

Each space can also be used in reverse as well by musical or other (small groups of) stage performers wishing to project sounds outward, or can double as seating for shows in the round.

Construction of the megaphones was financed by RMK and the interior architecture department of the EAA. Each was built offsite and carefully transported into place.

According to Valdur Mikita, a writer and semiotician involved in the project, “The trademark of Estonia is both the abundance of sounds in our forest as well as the silence there. In the megaphones, thoughts can be heard. It is a place for browsing the ‘book of nature,’ for listening to and reading the forest through sound.”