Researchers say that members of early farming communities in in the central Mediterranean preferred to paint images in rock shelters where sounds bounced off walls and into the surrounding countryside. Archaeologist Margarita Diaz-Andreu of the University of Barcelona and colleagues report that in landscapes with many potential rock art sites, "the few shelters chosen to be painted were those that have special acoustic properties."
     Diaz-Andreu's team studied two rock art sites generally dated to between approximately 6,500 and 5,000 years ago. In southeastern France, at the kilometer-long cliff site of Baume Brune, only eight of the forty-three naturally formed cavities in the cliff contain paintings, which include treelike figures and horned animals. On the east coast of Italy, in the Valle d'Ividoro, at an 800-metre-long section of a gorge, only three of eleven natural shelters contain painted images.
     The researchers popped balloons in front of each rock-shelter, recording the sound waves from various locations and distances. Three-dimensional slow-motion depictions of echoes revealed that at both sites, shelters with rock paintings displayed better echoing properties than undecorated shelters, and that shelters with the best echoes had the highest number of paintings.
     In a separate study of paintings in northern Finland dated to between around 7,200 and 3,000 years ago, music archaeologist Riitta Rainio of the University of Helsinki and her colleagues found that echoes from steep rock cliffs bordering three lakes also attracted ancient artists. She and her colleagues recorded from boats on the lakes.
     Similarly, at the Grotte de Niaux in southwestern France, archaeologist Paul Pettitt of Durham University in England observes that many roughly 14,000 to 12,000 year-old animal drawings and engravings are concentrated in a cathedral-like chamber where sounds echo loudly.

Edited from Science News (26 June 2017)