Non-invasive dating of historical church bells through vibroacoustic matching of musical temperaments

This study presents a non-invasive methodology for the chronological assessment of historical church bells based on vibroacoustic analysis and musical temperament matching. The method involves recording each bell’s acoustic emission, extracting the main spectral components, and comparing them to theoretical frequency sets derived from historical temperaments. Applied to eight bronze bells from Salerno Cathedral, dating from the 13th to the 19th century, the approach successfully identified a correspondence between each bell’s tonal profile and the temperament systems historically in use during its presumed period of origin. The results show a stratified pattern, with quarter-comma meantone tuning in the medieval bell and just temperament in most early modern specimens. Equal temperament appears in 19th-century examples. This confirms that tonal structures may serve as chronometric markers and opens a new direction in archaeometric research by recovering intangible heritage embedded in sound, without requiring any material intervention