A study of the effects of vocal intensity variation on children's voices using long-term average spectrum (LTAS) analysis

Abstract

Studies of adult voices have shown that, as vocal intensity is increased, the partials at higher frequencies gain more than those at lower frequencies. Investigations involving children's normal productions are uncommon, however, and there is, consequently, little knowledge of how children's vocal function differs from that of adults. Using LTAS analysis, this study investigates the effects of vocal intensity variation on the voices of 10-year-old schoolchildren singing in soft, mid and loud voice. A frequency-dependent gain factor was calculated which showed the increase in level to have been greater for partials at higher than at lower frequencies for these children. Also, gain within frequency bands was often different between boys and girls, although this was not demonstrated statistically.