It’s official, the world’s longest echo can be heard at an oil storage complex at Inchindown, near Invergordon in Scotland.  Hear it by hitting the play button above.

The 1970 Guinness Book of Records holds the last claim for the longest echo. When the solid-bronze doors of the Hamilton Mausoleum in Scotland slammed shut, it took 15 seconds for the sound to die away to silence. The Inchindown echo is a full minute longer.

Professor Trevor Cox of Salford University discovered the Inchdown echo while working with Allan Kilpatrick, an archaeological investigator for the Royal Commission on the Ancient and Historical Monuments of Scotland.

Allan fired a pistol loaded with blanks about a third of the way into the storage tank, and Trevor recorded the response picked up by the microphones about a third of the way from the far end – a standard technique used in concert hall acoustics.  At 125 Hertz, a frequency typically made by a tuba, the reverberation time was 112 seconds. Even at the mid-frequencies important for speech, the reverberation time was 30 seconds. The broadband reverberation time which considers all frequencies simultaneously was 75 seconds. They had discovered the world’s most reverberant space

All of this was just part of Trevor’s research on his new book, Sonic Wonderland: A Scientific Odyssey of Sound, published by Vintage Digital, part of the Random House Group.  It is an exciting journey for anyone who delights in audio treats, and a passionate plea for a deeper appreciation of, and respect for, our shared sonic landscapes.

Some of the other sounds can be heard here:

• Sonic Wonderland – The Great Stalacpipe Organ
• Sonic Wonderland – Bearded Seals
• Sonic Wonderland – Burping Sand Dune
• Sonic Wonderland – Kielder Forest, most tranquil place in England
• Sonic Wonderland – High-Tide Organ
• Sonic Wonderland – Musical Road

And as a footnote on that echo – here are some typical reverberation times at mid-frequency:

• ·         Living room: 0.4 seconds
• ·         Opera house: 1.2 seconds
• ·         Concert hall for classical music: 2 seconds
• ·         St. Paul’s Cathedral: 9.2 seconds