The position of the sound source in churches

The position of the sound source is an aspect rarely considered in room acoustics because the shape of the space and its internal organization generally make clear where the sound source should be. However, this may not be the case in some buildings, such as churches. In these buildings, the source is not located in one position, but it moves, from choir to the altar or the pulpit. This makes problematic the analysis of church acoustics. In particular, if the reverberation time is almost constant whenever the source may be, other acoustic parameters strongly depend on the position of the sound source. This paper mainly focuses on the effect of the position of the sound source over the early lateral fraction and the center time. After an historical evaluation of most common positions of sound sources, the results of computer simulations allow discussing the influence of some of them: above the entrance, in the middle of the room, between the altar and the worshipers, and behind the altar. Then, other acoustic parameters including the sound strength and the center time for different sound source positions are evaluated. Finally, suggestions to evaluate different positions of sound source in churches are reported.