Hundreds of people flocked to Greatstone on Saturday, September 1 as the Sound Mirrors, otherwise known as the Listening Ears were open for close up visits.
The three Sound Mirrors were built between 1928 and 1930 to detect enemy aircraft, in the years before radar. There are three types at Greatstone, two looking very like giant ears and the other more like a wall. But they all worked by using their curved surface to concentrate sound waves. A human listener would use a microphone and stethoscopes to pick up the noise and work out, using results from other mirrors, the height, flight path and speed of the approaching aircraft.
The Sound Mirrors can usually only be seen at a distance, across a lake, but occasionally they are opened to the public to raise money for the RSPB. This year, the beautiful weather attracted people in their droves from far and near including some locals who had never before had the chance to see them so close.
Many people decided to try to see if voices would travel across the 200ft wide wall. One person from each party went to the far end of the wall and the others stayed at the opposite end and pressed their ears to the bricks. The first person would whisper into and along the wall and the others would try to hear. Most of the phrases spoken were some variant of “can you hear me?”. Some people definitely could hear, but opinion was divided as to whether the wall was actually helping carry the sound, or whether in fact they could have heard perfectly well if the wall wasn’t there at all.
The Mirrors are always worth a visit, even if you can’t get up close. You can walk from the end of Taylor Road in Greatstone and get a great view across the lake of these eerily beautiful monuments. They can also be seen from the sky, for example on a Romney Marsh tour from Lydd airport.
Image Credits: Seana Lanigan , Environment Agency .