The ancient mystery revolving around the great acoustics of the Greek amphitheater in Epidaurus has finally been solved, according to Live Science. Scientists have been wondering about the high sound quality of Epidaurus’ theater for decades, developing certain theories along the way.
The ancient theater of Epidaurus was designed by Polykleitos in the 4th century BC. The original 34 rows were extended in Roman times by another 21 rows. It seats up to 14,000 people. The theater is admired for its exceptional acoustics, which permit almost perfect intelligibility of unamplified spoken words from the proscenium to all 14,000 spectators, regardless of their seating.
Over the years, several theories were developed in order to explain the phenomenon, both by academic and amateurs. Some of these theories suggest that prevailing winds carried sounds or masks amplified voices.
Researchers at the Georgia Institute of Technology have discovered that the limestone material of the seats provide a filtering effect, suppressing low frequencies of voices, thus minimizing background crowd noise. Further, the rows of limestone seats reflect high-frequencies back towards the audience, enhancing the effect, noted Live Science.
“When I first tackled this problem, I thought that the effect of the splendid acoustics was due to surface waves climbing the theater with almost no damping. While the voices of the performers were being carried, I didn’t anticipate that the low frequencies of speech were also filtered out to some extent,” said mechanical engineer Nico Declercq.
It is astonishing, however, that the Greek builders of the theater did not understand the principles that led to the exceptional audibility of sound from the stage.