The Acoustics of Contiones, or How Many Romans Could Have Heard Speakers

Contiones – assemblies during which important Roman politicians discussed the laws proposed at the People’s Assemblies as well as candidates for the offices and presented their opinions to the Roman people – are considered by some scholars as one of the central institutions and rituals of the Roman Republic. Considering the role contiones played in the political life of the Roman Republic, we can ask how many Romans participated in them. In our paper we present results of acoustic analyses of two places at the Forum Romanum that we know were platforms for speakers at contiones: the Rostra and the podium of the Temple of Castores. The main goal of our study was to establish the maximum number of participants that could have heard speeches inteligibly. To do that we used a 3D model of Forum Romanum considering not only the geometry but also the acoustic parameters of materials used to construct the rostra and adjacent constructions. Based on the sound power level of a speaker and possible noise sources, on which the recipients were exposed to, we established areas where speeches could have been heard and understood. This in turn allowed us to estimate the maximum number of recipients