Analysis of the acoustic response generated by the stairs of El Castillo of Chichen‐Itza in relation to the sound source.

Abstract

When a person claps in front the rebuild stairs of El Castillo in Chichen‐Itza, a chirp echo similar to the song of a quetzal is produced. This acoustic effect has been studied by many authors and some of them have proposed physical models to explain it. The simulations generated by these models were compared only with a recording using a handclap as sound source. In this work we analyze the response of the acoustic effect to different sound sources, and we propose a model based on a linear array of N point sources to simulate this response. A series of Gaussian pulses with different spectral distributions was reproduced and recorded in situ. It was found that above a frequency related to the steps dimensions, the acoustic response is temporally prolonged, and depending on the spectral distribution of the pulse, the response may result in a frequency sweep with one or more harmonics. Comparing the recordings with the simulations, it was found that the general characteristics of the acoustic response were reproduced by the model. With the results of this work, it is possible to know how the sound source, the stair dimensions, and receptor position are related with the acoustic effect.