+"Gender differences in children’s singing voices: Acoustic analyses and results of a listening test"
+https://asa.scitation.org/doi/10.1121/1.3372730
+> The listeners correctly identified the gender of the singer in 66.0% of the cases, i.e., far better than chance.
+
+"Listeners' Identification Of Gender Differences In Children's Singing"
+https://journals.sagepub.com/doi/10.1177/1321103X050240010301
+> 71.57% of identifications were positive
+
+----
+
+notes from Gender Development textbook—
+
+p. 6
+> Although there is some debate about whether this relatively rare condition should be considered a disorder at all (Bartlett, Vasey, & Bukowski, 2000), there are certainly some children who, from a very young age, show discomfort with their gender category.
+citation goes to Bartlett, N. H., Vasey, P. L., & Bukowski, W. M. (2000). Is gender identity disorder in children a mental disorder? Sex Roles, 43, 753–785.
+
+
+
+-----