Acoustic factors affecting the dynamic range of a choir.

Based on the assumption that individual sound intensities of singers are incoherent and add linearly to produce a combined choir intensity, a model of a voice range profile of a choir is produced. It is shown that this model predicts six distinct levels of choir dynamics (pp p mp mf f ff) over two octaves of fundamental frequency in a choir section. The levels are 3-6 dB apart, depending on the individual voice range profiles of the singers. Overall choir size has no effect on dynamic range, unless the size is varied dynamically by not all singers singing all the time. For a non-homogeneousn group of singers, a few loud voices dominate ff if everyone sings, while pp is not achieved effectively without suppressing all voices that cannot sing soft. Furthermore, the dynamic range can be significantly limited when choral blend for loudness is imposed on a non-homogeneous choir.