Acoustical characterization of touristic caves in Portugal

Since the Paleolithic, Mankind has been taking advantage of the acoustical characteristics of natural caves to perform its rituals. Nowadays many of these spaces are used as touristic attractions or even as stages for musical performances. This study characterizes three touristic caves in Portugal where in situ measurements were done, of background noise sound pressure levels, RASTI and Reverberation Time. The average RT values were 1.3 s to 1.7 s and the RASTI average values revealed good intelligibility (from 0.50 to 0.57). The sound absorption coefficient of the stone that constitutes the interior of those caves was also measured in a standing wave apparatus.