Comparing closed quotient in children singers' voices as measured by high-speed-imaging, electroglottography, and inverse filtering.

The closed quotient, i.e., the ratio between the closed phase and the period, is commonly studied in voice research.

Gender differences in children's singing voices: acoustic analyses and results of a listening test.

This study tested the hypothesis that acoustic parameters exist which are specific to gender in children's singing voices, and that these parameters are relevant to listeners' identification of gender of children's singing voices. A listening test was run with examples of singing produced by children belonging to different singing cultures, six boys and six girls from a Swedish music school and six boys from an elite German boys' choir. Sustained vowels were analyzed with regard to formants and voice source properties (jitter, shimmer and glottal-to-noise-excitation rate, closed quotient, and normalized amplitude quotient).

A virtual castrato?

In this investigation the voice source from trained boy singers was processed with a transfer function that contained the singer's formant cluster of a bass, a baritone, or a tenor. The modified voices were evaluated by a panel of highly specialized experts. The experts were asked 1) to assess how similar the examples sounded to the voice of the last castrato Alessandro Moreschi, and 2) to rate how similar they thought the examples were to their imagination of an 18th-century castrato voice.