The acoustic of Cumaean Sibyl

The Cumaean Sibyl cave is a mythological place in the north of Naples, where the Sibyl, a priestess presiding over the Apollonian oracle, received the travellers and predicted their future. The cave is length about 140 m, with trapezoidal section excavated in the rock of tuff. The cave has a height of about 4.5 m and it is 2.4 m wide. The legend says that the Sibyl received the travellers in the final part of the cave. Acoustic measurements were done with an omnidirectional sound source in the in the room inside the Sybil cave while positioning the microphones along the cave. An architectural acoustic software was then used to better understand the sound propagation in the cave. From acoustic measurement and numerical simulation results show that the voice emitted by an orator, positioned in the room inside the Sybil cave, is correctly understood in every point of this long tunnel. This shows that the legend that this site was used for by an oracle may have a scientific truth basis.