To prove that the valley people could have created a soundtrack, Baker and his colleagues tested the echo effect in the valley last September. The researchers invited musicians to play both high and low notes, and the test included Christopher Wells, a well-known Bavarian alphorn and trumpet player.
“If you think of needing the whole valley as an instrument, then it’s the alphorn that does it the most in the Alps,” Baker told LiveScience. “So we came down, and lo and behold we got amazing echoes at all these locations.”
In the experiment, two microphones faced the musician, and two others faced the rock art. One location required special noise filters to screen out the sounds of cars on a nearby highway.
“For our first field recordings, we used a surround-configuration,” said Astrid Drechsler, a sound engineer at the St. Pölten University of Applied Sciences in Austria. “During these first recordings the main focal point was on catching the atmosphere and spirit at these places.”