A prehistoric necropolis yields clues to the ancient use of sound and its effect on human brain activity.

Researchers detected the presence of a strong double resonance frequency at 70Hz and 114Hz inside a 5,000-years-old mortuary temple on the Mediterranean island of Malta. The ?al Saflieni Hypogeum is an underground complex created in the Neolithic (New Stone Age) period as a depository for bones and a shrine for ritual use. A chamber known as «The Oracle Room» has a fabled reputation for exceptional sound behavior.

Complete article at phys.org

More information at archaeoacoustics