Fundamental frequency onset and offset behavior: a comparative study of children and adults.

Short-term changes in vowel fundamental frequency (F0) immediately preceding (F0 offset) and following (F0 onset) production of voiceless obstruents were examined in groups of 4-year-olds, 8-year-olds, and 21-year-olds. Definitive patterns of laryngeal behavior were observed for each measure F0 was found to significantly lower at vowel offset across age groups, with no significant differences noted between groups, suggesting that F0 offset is simply an acoustic consequence of producing a voiceless obstruent preceded by a vowel. The F0 at vowel onset was high and significantly decreased thereafter. Age-related differences were identified for F0 onset with 4-year-olds in that their F0 rose to a lesser degree than that of adults. However, adult females demonstrated a greater change in both F0 onset and F offset behavior than adult males and children, suggesting that age-related differences in F0 behavior are likely to be influenced by sex. The results are discussed with regard to the physiologic constraints of F0 surrounding voiceless obstruent production in children and adults.