Long-Term Average Spectra from a Youth Choir Singing in Three Vocal Registers and Two Dynamic Levels

Few studies have reported the acoustic characteristics of youth choirs. In addition, scant data are available on youth choruses making the adjustments needed to sing at different dynamic levels in different registers. Therefore, the purpose of this study was to acoustically analyze the singing of a youth chorus to observe the evidence of the adjustments that they made to sing at two dynamic levels in three singing registers. The participants were 47 members of the Brooklyn Youth Chorus who sang the same song sample in head, mixed, and chest voice at piano and forte dynamic levels. The song samples were recorded and analyzed using long-term averaged spectra (LTAS) and related spectral measures. The spectra revealed different patterns among the registers. These differences imply that the singers were making glottal adjustments to sing the different register and dynamic level versions of the song. The duration of the closed phase as estimated from the amplitudes of the first two harmonics differed between the chest and head register singing at both dynamic levels. In addition the spectral slopes differed among all three registers at both dynamic levels. These acoustic measures may be a useful tool for evaluating some singing skills of young choristers.