1- "The team hikes up the narrow trail to the large mouth of Bédeilhac Cave, which was used as a military hangar by the occupying Germans during World War II."

1- "The team hikes up the narrow trail to the large mouth of Bédeilhac Cave, which was used as a military hangar by the occupying Germans during World War II." 2- "I’ve not heard about anyone using singing to echolocate, at least successfully. I use a percussive click, using my tongue and the roof of my mouth, and this is the technique that I teach, and it seems to be the most effective." 3-Through the process of gauging the resonance of the spaces, and therefore their shape and size, with his voice, he figured out that the most resonant parts of caverns are where the most cave paintings are located. 4- “There’s some evidence of the Navajo, the Iroquois, the Cherokee, the Acoma people of New Mexico, and the Nuxalk people of Canada using echolocation to determine ritual places” https://en.wikipedia.org/wiki/Ari%C3%A8ge_(department) https://en.wikipedia.org/wiki/Ari%C3%A8ge_(department)