Excavations at the Pre-Chavin site of Huaylas in the Peruvian Andes have revealed a specialized circular plaza designed for acoustic resonance. Unlike standard ceremonial platforms, this plaza features subterranean stone channels that amplify the sound of conch shell trumpets and rhythmic drumming. Archaeologists believe the site was the epicenter of a 'Festival of Echoes', where sound was used to induce trance-like states among participants during the spring equinox.
The discovery of bone-carved whistles and polished stone reflectors suggests a highly sophisticated understanding of ritual psychoacoustics. By channeling sound through the earth itself, ancient priests created a sensory experience that likely formed the foundation for later Andean festival traditions involving massive musical processions and communal chanting.