Directivity measurement in a choir of mixed voices

摘要

A choir of mixed voices is made up of a set of persons divided into four voices: sopranos, contraltos, bass and tenors. The usual situation of each one of the voices in a choir is the following: the low voices on the right of the director (contraltos ahead and bass behind) and the high-pitched voices on the left of the director (sopranos ahead and tenors behind). The directivity of each one of the four voices implied in a choir is a not fully studied topic, and even less known is the effect produced by the common situation in the choirs. This information can help us to organize the placement of the singers in a choir depending on the number of persons of each one of the voices. In order to study the directivity of each voice separately, as well as the effect produced by singing with a person ahead or behind or beside, it has been established a measurement method based on an array of microphones, regarding to which the different singers and groups (duets and quartets) turn around to make possible the obtaining of the horizontal, vertical and 3-D shape directivity.