Britain's vast cement "listening ears" designated a national landmark

Salim sez, "In the 1920s the British military used these vast concrete parabolic 'sound-mirrors' to detect approaching aircraft. The 'Listening Ears' at Denge have recently been designated as a historical preservation site by English Heritage, the government quango in charge of protecting national landmarks. From Wikipedia:"

Acoustic mirrors did work, and could effectively be used to detect slow moving enemy aircraft before they came into sight. They worked by concentrating sound waves towards a central point, where a microphone would have been located. However, their use was limited as aircraft became faster. Operators also found it difficult to distinguish between aircraft and seagoing vessels. In any case, they quickly became obsolete due to the invention of radar in 1932. The experiment was abandoned, and the mirrors left to decay. The gravel extraction works caused some undermining of at least one of the structures.

Denge sound mirrors (Thanks, Salim!)

[#1 posted by yezzer, March 3, 2009 4:36 AM]

Sadly you can't visit the sound mirror at Dungeness without a guided tour :(
I love this photo of it.

Incidentally, Dungeness is an otherworldly place. There's 2 nuclear power stations there, a wildlife reserve, and some of the weirdest scenery in the UK. Check out the flickr group.

Next time I go, I'm going to see "the boil"

[#2 posted by wolfrider, March 3, 2009 4:57 AM]

Just go to the ones set up in Golden Gate Park. Lovely low tech awesomeness.

[#3 posted by wgmleslie, March 3, 2009 5:34 AM]

Save one, lose the rest. This world has enough ugly concrete from WWII as it is.

[#4 posted by Clemoh, March 3, 2009 5:41 AM]

Those are beautiful.

[#5 posted by Anonymous, March 3, 2009 5:52 AM]

And Ive always wondered what a sound mirror was when I was listening to Clock DVA.

http://www.youtube.com/watch?v=qfMlbZqRQX0

Thanks Boing Boing for making me "that much smarter". :)

[#6 posted by Teapunk, March 3, 2009 6:10 AM]

I sense some Stonehenge in the making. If there are still people around in the year 4000, they will probably wonder what this was used for - a weird cult with human sacrifices? All country audio equipment?

[#7 posted by Moriarty, March 3, 2009 6:41 AM]

No jokes about giant British ears?

[#8 posted by Godot, March 3, 2009 6:50 AM]

"That's a spitting image of Prince Charles' ears!"

There.

[#9 posted by maoinhibitor, March 3, 2009 7:00 AM]

I'm really wondering what they sound like. Maybe they should be instrumented and hooked up to the 'net like the silophone.
http://www.silophone.net/

[#10 posted by RockinBrian, March 3, 2009 7:06 AM]

The acoustic mirror at Redcar (NE England) has a modern housing estate built around it. Video at http://www.youtube.com/watch?v=dUwA4yM4Wyo

[#11 posted by Beanolini, March 3, 2009 7:26 AM]

The Waalsdorp museum has an excellent collection of photos of more portable listening equipment; parabolic ear attachments, giant ear trumpets, etc.

I've been meaning to go and see the nearby Sunderland mirror for some time, but have never got round to it...

[#12 posted by blip, March 3, 2009 7:31 AM]

"the government quango"

The police state quango, surely?

[#13 posted by Moriarty, March 3, 2009 7:45 AM]

The civil liberties of those aircraft are being grossly violated by these police state surveillance devices. Tear them down!

[#14 posted by Anonymous, March 3, 2009 7:59 AM]

Yes, but what are the implications of hooking you kindle to 'em and beaming TTS speech to France? (ducks, runs away...)

[#15 posted by nereus, March 3, 2009 8:01 AM]

Why is this not entitled 'steam punk radar'?

[#16 posted by kleer001, March 3, 2009 8:26 AM]

they also feature in a bang up gobsmackingly gorgeous promo video from Coldcut in the song "Sound Mirrors" : http://www.youtube.com/watch?v=-kRNIQMKnD8

[#17 posted by dculberson, March 3, 2009 9:15 AM]

WGMLeslie, Concrete is not ugly. (And I'd definitely argue with the 1920's being "from WWII.")

[#18 posted by seric, March 3, 2009 9:16 AM]

I disagree strongly with #3. We should preserve what evidence we have of our collective history. And leaving as many examples up as possible increases accessibility, and provides redundancy in the event of some event destroying a singular example.

[#19 posted by mralistair, March 3, 2009 9:18 AM]

concrete not cement

cement is a powder you make concrete with

/pedant

but they are rather nice.

[#20 posted by Anonymous, March 3, 2009 9:24 AM]

Funny, The Prodigy's video "Invaders must die" from their new album is shot at the same location. I watched it yesterday for the first time and tried to figure out what these strange buildings were used for. http://www.youtube.com/watch?v=EiqFcc_l_Kk

[#21 posted by squintsideways, March 3, 2009 9:25 AM]

These could be a monumental icon of Britain's surveillance society.

[#22 posted by Cpt. Tim, March 3, 2009 9:26 AM]

i've sat in smaller scaled versions of these things and its amazing how well they work. i was a few hundred feet away from someone and we could hear each other at conversation levels.

[#23 posted by IWood, March 3, 2009 9:48 AM]

I have an irresponsible plan in my head...I'm still foggy on the details, but it involves motorcycles and racquetball...

[#24 posted by Takuan, March 3, 2009 10:11 AM]

set off acetylene filled balloons at the focal point.

[#25 posted by Anonymous, March 3, 2009 10:37 AM]

Dude! I could totally skate that!!

[#26 posted by bucky888, March 3, 2009 10:46 AM]

The Acoustic Mirrors feature in The Scarifyers Devil of Denge Marsh. BBC Radio 7 plays this over the internet on an occasional basis.

[#27 posted by mork the delayer, March 3, 2009 11:33 AM]

Here is a link to the Denge Acoustic mirrors on google maps.

[#28 posted by Flying_Monkey, March 3, 2009 1:46 PM]

The artist Joe Banks (AKA Disinformation) made a fantastic installation piece called Blackout using sound recordings and images from these sites along with recordings of military burst transmissions back in the late 90s. He's just put a version of this up on youtube:

http://www.youtube.com/watch?v=qsR3qyJDk0c

[#29 posted by TedJohnson, March 3, 2009 5:11 PM]

@25 This dude could totally skate that (but perhaps not on the first attempt).

[#30 posted by dimmer, March 3, 2009 8:47 PM]

Re: "the government quango"

As quango is an abbreviation of quasi-autonomous non-governmental organisation", #12's suggestion may well suit better!