Computer simulation of the acoustics of the Ear of Dionysius (Syracuse-Italy) in order to evaluate objective descriptors of speech intelligibility

A myth handed down for a long time says that the tyrant of Syracuse Dionysius I (the Elder, ca. 432–367 BC) could understand the speech of war prisoners through a window in the upper part of the innermost wall of the grotto named Ear of Dionysius. Sabine himself who had visited this cave had cast serious doubts on this possibility [1]. Few years ago the authors carried out a set of acoustic measurements to characterize the acoustics of this site known worldwide for its peculiar reverberation [2]. Unfortunately, they could perform only a single measurements of the sound transmission from the floor level of the grotto to the listening spot of the tyrant to estimate a degree of truth of the myth. This paper reports a numerical study of the acoustics of the Ear of Dionysius aimed at the evaluation of current roomacoustics parameters related to speech intelligibility when a speaker is located at the ground level of the cave and the listener occupies the supposed spot of the tyrant. The roomacoustics simulation was carried out with the aid of the specialized software Odeon.11 [3]. The results of the simulation still suggest reasonable doubts about the possibility the tyrant could understand the speech of prisoners