Because of its Gothic style architecture Myeong

Because of its Gothic-style architecture, Myeong-dong Cathedral was selected to study its acoustical characteristics. The architectural acoustics and electro acoustics characteristics were compared and analyzed using acoustical measurements. This study was conducted as follows: investigation of construction specifications and indoor finishing materials of the Myeong-dong Cathedral, acoustical measurements in the cathedral with regard to an omni-directional speaker sound source and the public address system sound source based on ISO 3382-1 (ISO, 2009) and calculation of the acoustical parameters, comparison and analysis on acoustical parameters with regard to the two sound sources, and subjective evaluation of the acoustical characteristics and satisfaction of the congregation of the cathedral with regard to the two sound sources.
Acoustical measurements and subjective evaluation
Results of the acoustical measurement
Results of the subjective evaluation The response of the subjects on the evaluation is shown in Fig. 13. The scores ranged between 3.31 and 3.92, and the overall average was 3.68, which indicated that subjects were satisfied overall with the sound environment (voice and music recognition and background noise) in Myeong-dong Cathedral. The only parameter that had below the average satisfaction was balance between low and high sounds in music recognition. Pearson׳s correlation coefficients between the acoustical parameters and results of the subject evaluation in Myeong-dong Cathedral were calculated to examine the relationship between the quantitative data and the qualitative data, and the results are listed in Table 2. There was positive correlation between “Voice – intelligibility” and SPL, C80, and D50 (correlation coefficients are 0.62, 0.70, and 0.61, respectively), while there was a negative correlation between “Voice – intelligibility” and ITDG (correlation coefficient is −0.78). One explanation for this is that people׳s perception of speech intelligibility was influenced positively by favorable sound pressure levels and voice clarity, whereas it tegaserod was influenced negatively by the initial reverberation. A positive correlation was found between “Music – clarity” and RT60 (correlation coefficient is 0.67). There was positive correlation between “Music – reverberation” and EDT and C80 (correlation coefficients are 0.74 and 0.62, respectively), while there was a negative correlation between “Music – reverberation” and SPL, D50, and RASTI (correlation coefficient are −0.69, −0.68, and −0.73, respectively). In addition, positive correlations were found between “Music – intimacy” and EDT and RT60 (correlation coefficients are 0.61 and 0.62, respectively), while negative correlations were found between “Music – intimacy” and D50 and RASTI (correlation coefficients are –0.60 and −0.61, respectively). One explanation for this is that people׳s perception of reverberation of sound was influenced positively by favorable reverberation and music clarity, whereas segments was influenced negatively by sound pressure levels and voice clarity. The similar tendencies were found between the acoustical parameters and results of the subjective evaluation by statistical analysis. It can be explained that speech intelligibility in the voice recognition was influenced positively by favorable sound pressure level (SPL) and clarity of voice (C80 and D50), whereas it was influenced negatively by the initial reverberation (ITDG). Meanwhile, reverberation of sound in the music recognition was influenced positively by favorable reverberation (EDT and RT60) and clarity of music (C80), whereas it was influenced negatively by sound pressure level (SPL) and clarity of voice (D50).
Concluding remarks Seven acoustical parameters were calculated from the acoustical measurements conducted in Myeong-dong Cathedral, the Roman Catholic Archdiocese of Seoul, which is the first built Western Gothic-style architecture in Korea. The results were as follows: SPL (64.6 dBA on average), EDT (4.04s on average), RT60 (3.58s on average), C80 (−6.2dB on average), D50 (18% on average), ITDG (47ms on average), and RASTI (32% on average). Although the above results had considerably low efficiency in terms of sound pressure and clarity, they provided an appropriate acoustic environment for classical church music such as a monophonic chant, unaccompanied choral music, and pipe organ music in terms of reverberation time.