Roman Theatres and Revival of Their Acoustics in the ERATO Project

Abstract

The ERATO project wasat hree-year research project financed by the European Commission under the Fifth Framework INCO-MED Program (2003-2006. The acronym refers to the project title: Identification, Evaluation and Revivalofthe Acoustical Heritage of Ancient Theatres and Odea. The ancient Greek and Roman theatres are famous for their excellent acoustics. However, it is not generally well known that different kinds of theatres were built, for different purposes and with different acoustical conditions. The development of the Roman theatre types (theatre, odeon and amphitheatre)p articularly in the first Century BC is briefly outlined. One aim of the ERATO project has been to investigate the acoustics of the open air theatre and the odeon, using virtual reconstructions be means of computer models of the spaces, completed in accordance with available archaeological information. Musical instruments and short pieces of music have been reconstructed and recordings have been used for auralisation of some theatre scenarios. Ancient Greek and Roman theatres are often considered acoustically perfect. However, the semicircular shape of the audience area in theatres may cause acoustic problems, and there is also evidence that the ancient architects were aware of this. The Roman architect Vitruvius mentions in his famous books on architecture four different kinds of sound reflections in at heatre, one of them called 'circumsonant' which is probably the acoustical phenomenon that we today would name afocused echo. Computer simulations of some examples of ancient Greek and Roman theatres confirm that echo can occur at some places in the audience area. Apossible solution to these echo problems could be the introduction of sound absorption in the vertical, concave surfaces in away similar to that described by Vitruvius for the sounding vessels, i.e. in niches between the seats arranged in ahorizontal range halfway up (inthe diazoma). Thus it makes sense if the vessels were supposed to act as sound absorbing resonators, although the number of resonators is farfrom sufficient for having anyreal effect. The idea and principle of installing resonators in atheatre comes from Aristoxenus (4th century BC), who wasafamous Greek philosopher and scholar in music theory.Itisconcluded that the sounding vessels had no practical importance in the Roman theatres, and Vitruvius wasn ot up-to-date in his writing on theatre design, butrelied heavily on older,Greek references. PACS no. 43.55.Gx, 43.55.Ka Received2May 2012, accepted 2October 2012.popular newer building types in Roman cities. As abackground it is important to have acloser look at the context of Vitruvius' books, and particularly the remarkable development of theatre types during the first century BC.The EU project ERATO has dealt with virtual reconstructions and acoustical simulations of selected theatres and odea. Acoustical measurements were also made, particularly interesting in the Aspendos theatre because this is one of the best preserved Roman theatres today.W ith the characteri...

Measurements of Acoustical Parameters in the Ancient Open-Air Theatre of Tyndaris (Sicily, Italy)

“…In an open-air theatre, when the sound field substantially differs from a diffuse field, reverberation time is not in principle applicable, but despite this, it is largely used for the acoustic qualification of ancient theatres and for their comparison [2,3,10,21,47]. The main contributions to reverberation are few energetic reflections and the scattered sound energy coming from the steps in the cavea.…”

“…In recent years, there has been a growing interest in the acoustical characterization of ancient open-air theatres, which led to the development of several research projects (see, e.g., in [1][2][3][4]) and a prolific production of scientific literature on the topic (see, e.g., in [5][6][7][8][9][10][11][12][13][14]). This reflects a general trend observable in the broader field of archaeoacoustics [15].…”

The Accuracy of Predicted Acoustical Parameters in Ancient Open-Air Theatres: A Case Study in Syracusae

“…Different considerations on ancient theatre measurements, defined during the European ERATO Project [3], were taken into account. The measurement results for SR have been used in Section 4 for the calibration of the simulation model and as references for the acoustic parameters predicted through computer simulations.…”

“…A preliminary benchmark test study was carried out on SR, whose model had previously been used in different investigations, e.g., simulations concerning its ancient conditions, during the European ERATO project, [3] and in investigations on its contemporary use [25]. Figure 3a shows the 3D model configuration of SR.…”

“…The ISO 3382-1 standard [2] was used in the European ERATO project [3] to evaluate the acoustical apparatus of ancient theatres through room acoustic parameters, such as the Early Decay Time (EDT), Reverberation Time (RT), Clarity (C 80 ), and Sound Strength (G). However, ISO 3382-1 basically refers to indoor environments and temporal decay parameters seem to be less suitable for open-air conditions [4][5][6][7][8].…”