The Sound Emission of the Bell Tower of the Salerno Cathedral in Medieval Europe between Architectural Structure and Bell Construction Techniques

This study aims at understanding the intangible design principles that may have directed the design and construction of the Bell Tower of the Salerno Cathedral. The starting point is the hypothesis, already well demonstrated in previous papers, that this bell tower is one the key source elements of a largely distributed network of communication and government of the territory based on the acoustic transmission of information, relying on sources and repeaters (bells towers of monasteries, churches, towers and castles), synergically coordinated by Normans and Benedictines. In particular, the study focuses on the top part of the Bell Tower, the turret, that housed the bells during the Norman period. The results demonstrate that the turret behaves as an acoustic resonator matched to the bell’s sound emission, to maximize and concentrate the acoustic emission in defined directions, changing the vision on the level of acoustic knowledge and the quality of implementations in the Norman period.