We might think of a cave as a peaceful place
but put humans into the equation
and it can become quite unnervingly noisy.
Last week Gizmodo featured a BBC video about the subterranean acoustics of Spanish caves and an explanation of how archaeologists are using the sounds to locate ancient art. Just listen:
Sarah Zhang, "Using Subterranean Acoustics to Explore Ancient Cave Art", Gizmodo, February 13, 2014
"Songs of the Caves: Acoustic and Prehistoric Art in Spanish Caves", February 21, 2013