The Acoustics of Rock
last updated May 26th, 2002 and is permanently morphing...
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THE ACOUSTICS OF ROCK ART
S. Waller has visited rock art
sites in Europe, North America, and Australia.
Standing well back from the painted walls, he claps or creates percussion
sounds, and records the echos bouncing back. A casual observer might be
tempted to call 911. It turns out, though, that rock art seems to be placed
intentionally where echos are not only unusually loud but are also related
to the pictured subject matter. Where hooved animals are depicted, one
easily evokes echos of a running herd. If a person is drawn, the echos
of voices seem to emanate from the picture itself!
"At open air sites
with paintings, Waller found that echos reverberate on average at a level 8
decibels above the level of the background. At sites without art the average
was 3 decibels. In deep caves such as Lascaux and Font-de-Gaume in France,
echos in painted chambers produce sound levels of between 23
and 31 decibels. Deep cave walls painted with cats produce sounds from
about 1 to 7 decibels. In contrast, surfaces without paint are 'totally
(Dayton, Leigh; "Rock Art Evokes
Beastly Echos of the Past," New Scientist, p. 14, November 28, 1992.)