The acoustic bases for gender identification from children's voices

The purpose of this study was to examine the acoustic characteristics of ch ildren's speech and voices that account for listeners' ability to identify gender. In Experiment I, vocal recordings and gross physical measurements o f 4-, 8-, 12-, and 16-year olds were taken (10 girls and 10 boys per age gr oup). The speech sample consisted of seven nondiphthongal vowels of America n English (/ae/ ''had,'' /epsilon/ ''head,'' /i/ ''heed," /I/ "'hid,'' /a/ ''hod,'' /Lambda/ ''hud,'' and /u/ ''who'd'') produced in the carrier phras e, "Say/hVd/again." Fundamental frequency (f(0)) and formant frequencies (F 1, F2, F3) were measured from these syllables. In Experiment II, 20 adults rated the syllables produced by the children in Experiment I based on a six -point gender rating scale. The results from these experiments indicate (I) vowel formant frequencies differentiate gender for children as young as fo ur years of age, while formant frequencies and fo differentiate gender afte r 12-years of age, (2) the relationship between gross measures of physical size and vocal characteristics is apparent for at least 12- and 16-year old s, and (3) listeners can identify gender from the speech and voice of child ren as young as four years of age, and with respect to young children, list eners appear to base their gender ratings on vowel formant frequencies. The findings are discussed in relation to the development of gender identity a nd its perceptual representation in speech and voice. (C) 2001 Acoustical S ociety of American.