Effect of Forms and Shapes on Acoustical Quality of Ecclesiastical Buildings in Nigeria

This research work looks at how selected architectural forms and shapes influence the acoustical performance of religious structures in Nigeria in areas of RT60, SPL, and SII. Using data from urban cathedrals, Pentecostal churches, and traditional indigenous churches, the paper discusses how logarithmic volumes, material choices, and geometric patterns affect acoustic experiences during prayers. Due to high roofs and large open spaces, urban cathedrals showed high RT60 values (3.8–4.2 s) and uneven sound distribution, making speech intelligibility low. Some Pentecostal churches had lower values of RT60 (1.6 – 2.2 sec) but that was worsened by sound amplification with such problems as sound distortion and SPL imbalances in the range of 85- 105dB. However, traditional churches with small volume and sound absorption materials like mud and wood almost reached the recommended RT60 value of between 1.2 and 1.8 seconds and had excellent speech transmission index of 0.85 to 0.88. This research work employed a mixed-method approach which is the qualitative and quantitative methods. From these deductions, there is a need to incorporate acoustic principles in the church design concerning good speech and music clarity. Therefore, the study recommends a partnership effort by the architects, acousticians, and sound engineers to compensate for the complexity emanating from poorly designed contemporary church architectural design while capitalizing on the better acoustics of the historical structures. In doing this, Nigerian ecclesiastical buildings can achieve the development of aesthetic spaces that will not just spiritually and audibly inspire the worshippers.