The strange sound of Wormit water reservoir
19 December 2012 Last updated at 17:41 GMT
Trevor Cox, a professor of acoustic engineering at the University of Salford, has identified Wormit water reservoir as one of the strangest sounding places in the UK.
Like a cathedral, the sound takes a long time to die away in the decommissioned reservoir near Dundee.
The clip is of a balloon being burst in the reservoir.