Startling distortions of footsteps and voices in this incredibly atmospheric foot tunnel.
(9 Votes, average 3.78)Loading...
Is it just me, or is it virtually impossible to resist the urge to shout and whoop when you’re in a tunnel? I’ve noticed that some tunnels work better than others, and this one under the Thames near Greenwich, London is remarkably effective. A study by artist Peter Cusack found this soundscape to be one of London’s favourite sounds [1]. The sound qualities mentioned in the study included the amazingly long reverberance and echoes as well as the acoustic distortions to familiar sounds such as footsteps and voices.
The hard tiled surfaces allow the sound to rattle back and forth in the tunnel for a long time before dying away. What’s more, sound takes ages to go up and down the length of the tunnel, which leads to amazingly long echoes.
Logistics
The south end of the tunnel is at Cutty Sark Gardens, Greenwich, London. The north end is at Island Gardens. It’s open 24 hours a day, but has a hundred steps at either end.
The chimes of Big Ben ringing out from the Houses of Parliament’s clock tower is arguably the the most famous sound of London. Indeed, a study by artist Peter Cusack showed it to be one of Londoner’s favourite sounds. However, most British people probably recognize this from the ‘bongs’ on the TV and radio news, rather than something they heard on a London street. The Big Ben bell celebrated it’s 150th anniversary in 2009. It’s a mammoth 13.5 tons. It cracked a few months after installation and needed repairing when too heavy a hammer was used.
Logistics
Currently not sounding due to rennovation. Normally, on the streets close to the tower the chimes are clearly audible. But as you go further away it gets harder to hear as traffic noise masks the sound. It’s easier to hear higher up so surrounding buildings are not getting in the way. It’s possible to book a tour of the the tower, but you need to contact your member of parliament or get sponsored by a peer months in advance.
St Paul’s Cathedral is an iconic building in the centre of London. High up in the central dome is a Whispering Gallery, which I remember visiting as a child. Climb 259 steps inside the dome, stand on one side of the circular gallery and talk very quietly and your speech can be heard quite clearly on the other side some 30m away.
St Paul’s is a circular whispering gallery. In this case, sound hugs the walls, allowing it to move from one side of the room to another without getting a lot quieter – the diagram shows some of the paths that the whispers take around the perimeter of the gallery.
Sound paths in a circular whispering gallery
Location and Logistics
St Paul’s Cathedral, St Paul’s Churchyard, London, EC4M 8AD. It’s worth arriving early in the morning and going straight to the Dome, because once the space gets busy it’s hard to pick out the whispering gallery effect amongst the hubbub.
Acoustic mirrors were an attempt to detect enemy aircraft flying towards England in the early twentieth century.
(11 Votes, average 3.55)Loading...
These amazing structures are sound mirrors. Concrete concave dishes designed to capture the sound of incoming enemy aircraft as they flew over the north sea and the channel towards England. Acting on sound like a concave shaving mirror focusses light, the sound from the aircraft is concentrated to a point where a microphone picks up the sound. The largest structures allowed aircraft to be detected 6.5 miles away, as well as determing the direction of attack to an accuracy of 1.5 degrees [4]. Overall they were not terribly effective, however, and became obsolete and abandoned when RADAR was invented.
Sound mirror, Kilsnea, Yorkshire {1}. The focussing point where the sound is concentrated is at the top of the metal pole.
At Kilnsea, Yorkshire, UK the mirror is about 4.5m high. It was used in World War I to try and pick up the engine noise from Zeplin aircraft. This gave 3-4 minutes of extra warning before attack [2]. Zeppelins raided the North East of England fifteen times between 1915 and 1917.
3 Sound mirrors, Denge {3}
At Denge, Kent, UK there are three mirrors. The various acoustic mirrors were constructed in the 1920s & 1930s. The different designs are evidence of experimentation to discover which shape and size worked best. There are a 6m concrete concave mirror, a 9m hemispherical bowl and a curved 60m long mirror.
Logistics
Easy to visit
Abbot’s cliff sound mirror {6}
1. Abbot’s Cliff, Kent, UK: grid reference TR27083867. A ten minute walk from the Folkestone – Dover road along a tarmac path [5].
Sound mirror at Hythe {6}
2. The Roughs near Hythe, Kent, UK are on MoD property but several websites say the dishes can be visited. The picture is of a 9m mirror, a smaller 6m mirror lies nearby on its face [5].
3. The Redcar sound mirror is in a modern housing estate at the junction of Holyhead Drive and Greenstones Road.
Sound mirror Sunderland {8}
4. In Sunderland alongside a bridleway about 200 metres west off the Newcastle Road, Fulwell.
On private land and probably only viewable from a distance
1. Boulby, Yorkshire, UK: West of Boulby Barns Cottage on Boulby Bank. On private land, although the rear of the mirror is visible from a nearby minor road [5].
2. Kilnsea, Yorkshire, UK: Not far from a road but on private land.
3. Il Widna (“The Ear”), Malta: On private land but can be seen from a distance through a fence [5]. Large curved strip mirror similar to the large device at Denge.
Accessible only on a guided tour
Denge, near Dungeness, Kent, UK. These are not accessible to the public except via guided walks by. [5]
An amazing cacophony in the largest covered public square in Europe
(5 Votes, average 4.20)Loading...
This place has a remarkable acoustic which complements the beautiful architecture. Opened in 2000, the court wraps around the circular central reading room, providing a huge circulation space with cafes, information points and shops. The sound of people talking and walking echoes throughout the space. The soundscape is a cacophony of indistinct speech and other blurred sounds.
Large reverberant spaces are familiar to us all, but the sheer size of the Great Court along with the number of people creating the sound makes this space ear-conic. The only downside to the great sound effect is that it makes conversations difficult to hold in the cafes – as I found out when I foolishly tried to hold a business meeting there.
Incidentally, audio nerds can also wander around and look for the Intellivox loudspeakers; an interesting technology which attempts to make public address announcements intelligible in cavernous spaces.
Logistics
The British Museum, Great Russell Street, London, WC1B 3DG. Can only be visited when the museum is open. The Great Court is free to enter. Most impressive when busiest (weekends, school holidays etc.)
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![Sound mirror at Hythe [6]](http://www.sonicwonders.org/images/sound mirror hythe.jpg)
