This graphic has been making the rounds at several websites and forums
recently. It's from the book "America's Munitions 1917-18" by Benedict
Crowell and apparently shows the sound of the end of WWI:
From my limited Googling around, this appears to have been created by a
military sound ranging system using low frequency microphones that was in
development during the War.
Are there any more original examples of these recordings that survive in
their original form and not as reproductions in books? Patrick Feaster
know about this?
Randy A. Riddle