Improving acoustical characteristics of a Gothic cathedral using simple public address system: A case study of Myeong-dong Cathedral in Seoul, Korea

Abstract

In the present study, improving acoustical characteristics of a Gothic cathedral (Myeong-dong Cathedral, which is the first built Western Gothic-style architecture in Korea) using simple public address system were investigated. Acoustical measurements were conducted at 11 selected points inside the cathedral and seven acoustical parameters were calculated: sound pressure level (SPL): 64.6 dBA (the measurement value with regard to the omni-directional speaker sound source);74.5 dBA (the measurement value with regard to the public address speaker sound source), early decay time (EDT):4.04 s; 3.76 s, reverberation time (RT₆₀): 3.58 s; 3.89 s, clarity (C₈₀): -6.2 dB;-2.8 dB, definition (D₅₀): 18%; 29%, initial time delay gap (ITDG): 47 ms; 23 ms, and rapid speech transmission index (RASTI): 32%;42%. Parameters showed that the acoustical characteristics of a typical Gothic cathedral include rich reverberation and diffusive sound fields. Meanwhile,there was improved speech intelligibility when using simple public address system. Based on subjective evaluation, there was overall satisfaction with voice and music recognition and the highest satisfaction with clarity with respect to voice recognition and with reverberation with respect to music recognition. This is a good solution of optimized acoustic environment through harmony between natural reverberation and reinforced clarity using simple public address system.

Key words： Gothic cathedral; Acoustical characteristics; Public addresssystem; Clarity; Reverberation