Relationships between subjective and objective acoustical measures in churches

This study reports on subjective and objective acoustical field measurements made in a survey of 36 Catholic churches in Portugal built in the last 14 centuries. Monaural acoustical measurements (RT, EDT, C80, D50, TS and L) were taken at several source/receiver locations in each church and a group of college students was asked to judge the subjective quality of music. The listeners in each church evaluated live music performances at similar locations in each room. Evaluation sheets were used to record the listeners overall impressions of room acoustic quality and also Loudness, Reverberance, Intimacy, Envelopment, Directionality, Balance, Clarity, Echoes and Background Noise. This paper concentrates on the relationships of the subjective parameters with the objective room acoustics measures and with the architectural features of the churches. Correlation analyses and statistical modeling identified significant relationships among the measures. For instance, linear correlation coefficients (R) of 0.8-0.9 were found for the relationships: Reverberance/RT and Clarity/C80; the maximum R found was 0.93 for Echoes/RT. Regarding architectural features the maximum R found was 0.87 between Intimacy and Total Volume