Mystery of 'chirping' pyramid decoded

[Dover]

Mystery of 'chirping' pyramid decoded



Acoustic analysis shows how temple transforms echoes into sounds of nature.

A theory that the ancient Mayans built their pyramids to act as giant resonators to produce strange and evocative echoes has been supported by a team of Belgian scientists.

Nico Declercq of Ghent University and his colleagues have shown how sound waves ricocheting around the tiered steps of the El Castillo pyramid, at the Mayan ruin of Chichén Itzá near Cancún in Mexico, create sounds that mimic the chirp of a bird and the patter of raindrops1.

The bird-call effect, which resembles the warble of the Mexican quetzal bird, a sacred animal in Mayan culture, was first recognized by California-based acoustic engineer David Lubman in 1998. The 'chirp' can be triggered by a handclap made at the base of the staircase.

Declercq was impressed when he heard the echo for himself at an acoustics conference in Cancún in 2002. After the conference, he, Lubman and other attendees took a trip to Chichén Itzá to experience the chirp of El Castillo at first hand. "It really sounds like a bird", says Declercq....cont'd

http://www.nature.com/news/2004/041213/full/041213-5.html

[mr_hat]

1. My cell phone chirps. Progress...