Technical Note The acoustics of the caves Gino Iannace ⇑ , Amelia Trematerra Department of Architecture and Industrial Design, Second University of Naples, Borgo San Lorenzo, 81013 Aversa (Ce), Italy article info Article history: Received 21 April 2014 Received in revised form 11 May 2014 Accepted 19 May 2014 Keywords: Caves Underground places Room acoustics abstract This work shows the acoustic measurements realized at three underground places: the caves of Pertosa or of the Angel, the caves of Castelcivita and the caves of Castellana. These places are used for some years to represent music and theater performances, whose success is also due to the mystery and the charm that distinguish them, based on the natural setting of the caves. The places of the caverns where the shows are played were characterized analyzing the monaural acoustic parameters (T 30 , EDT, C 80 ,D 50 and Rasti) obtained with the impulse response resulting from blowing up some balloons inside them. The values of monaural acoustic parameters measured in the caves can be compared with the parameters of the con- cert halls currently in use. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction The acoustics of the underground places has also drawn the attention of archaeologists and anthropologists because studying them it could be possible to deduce useful information about the prehistoric man behaviors [1]. There are strong elements support- ing the hypothesis that during prehistory the caves with special acoustic properties were used for ritual ceremonies with songs, music and dance, although in European caves rock engravings rep- resenting human figures are rare and even less in attitudes regard- ing activity related to music or dance, in fact most of the subjects are animals. Some studies have been performed with acoustic measurements in situ to evaluate the possible relationships between the acoustics, the graffiti painted on the walls of the caves and the evidences discovered [2,3]. The use of caves for musical performances during modern times comes from the second half of the ‘700 when in the Caves of Osselle (France) [4], illuminated with torches, were performed music and dance. In 1822, the Postu- mia Caves in Slovenia were opened to the public for dancing par- ties with popular music and for public events. The cave of Romanesti, in Romania, on the Poiana Rusca mountains in the Transylvanian Alps, hosts regularly charming concerts followed by a few thousand people. In the Greek island of Kefalonia, the cave of Drogarati is accessible the room of Apotheosis, a nearly semicir- cular room, that, thanks to its good acoustics, hosts concerts and other events during the summer with about 500 spectators. The ‘‘Cueva de Nerja’’, a cave near Malaga (Andalusia, Spain), was dis- covered in 1959; starting from the ’60 s it was equipped with a large stage placed in front of a natural backdrop in the Room of Waterfall and for many years there are shows of symphonic music, ballet, flamenco and other genres. In Lanzarote, in the Spanish archipelago of the Canary Islands, there is a system of tunnels and caves that was formed more than 3000 years ago as a result of the eruption of the volcano La Corona; in 1968 the artist archi- tect Cesar Manrique designed inside it an accommodating, cultural and natural complex, called ‘‘ Jameos del Agua ‘‘, and inside one of the largest galleries in 1987, was completed the adaptation of an Auditorium with a capacity of about 550 seats. The caves of the Angel in the town of Pertosa (in South of Italy), dating back to 35,000 years ago, have been visited by people since the Bronze Age (2nd–3rd millennium BC). The initial part of these caves is crossed by an underground river, the entrance is on board of a barge and it has a landing inside from which begins paths and rooms along three directions, whose geo-morphological character- istics are such that they have inspired a natural scenery for perfor- mances. In addition to ‘‘The Dante’s Inferno’’ [5], in Pertosa takes place for more than fifteen years a festival of ethnic music (Negro) and occasionally also other forms of musical performances and concerts. Fig. 1 shows a schematic plan of the caves of the Angel, in the parts of touristic path. Not far from Pertosa there are the caves of Castelcivita, a karst cave inhabited during the High Paleo- lithic in which have been found human artifacts, also in this site the play ‘‘Orpheus and Eurydice’’ is represented for some years; it is a traveling performance made along a path of approximately 1 km, with plays, dances and songs. The site is really interesting for geologists, spelunkers, paleontologists and archaeologists because the fossils and stone tools found are the proof of a human http://dx.doi.org/10.1016/j.apacoust.2014.05.004 0003-682X/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +39 3393742507; fax: +39 82445010. E-mail address: gino.iannace@unina2.it (G. Iannace). Applied Acoustics 86 (2014) 42–46 Contents lists available at ScienceDirect Applied Acoustics journal homepage: www.elsevier.com/locate/apacoust