The contributions made by the Ancient Greeks to the world of acoustics are unparalleled.
One of them is the amphitheatre of Epidaurus, designed by Polykleitos the Younger, around the 4th century BC. The theatre had a tripartite structure, that is, an orchestra, auditorium, and stage building. There were also 34 rows of limestone seats that could accommodate 14,000 people.
The acoustics of the place was such that a performer standing on the open-air stage could be heard in the back rows, almost 60 metres away.
Experts attribute this rare feature to the arrangement of seats. According to them, the stepped row of seat structure was perfectly shaped so as to act as an acoustic filter. The seats suppressed low-frequency sounds that formed the major component background noise like the murmur of a crowd. This in turn, reflected high-frequency noises of the performers off the seats, and back toward the seated audience.