Characterizing the indoor acoustical climate of the religious and secular rock-cut structures of Cappadocia

Rock-cut structures of Cappadocia, which are enlisted as natural and cultural World Heritage Sites by UNESCO, have particular acoustics due to the specific tuff stone belonging to the region. This study, for the first time, discusses the indoor sound fields of the Cappadocia over five selected spots (one church and four residential halls) from Middle Byzantine sites of Hallaç, Açıksaray and Avanos with an aim of providing evidence regarding the spatial features and culture of the people inhabited these spaces. Acoustical data is collected during in-situ field tests. Acoustic parameters (EDT, T20, T30, C80, CD50, and STI) are obtained for the spaces under study. The rock-cut church is found to be the most reverberant among all the spaces and the most suitable for liturgical practices. The other four spaces are observed as comparatively more favorable for speech-related activities. The study also compares the sound absorption performance of Cappadocian tuff stone to those present in other natural caves and rock-cut structures investigated throughout the world in few prominent studies