Susan Nittrouer
Univ. of Nebraska at Omaha, Omaha, NE 68182
Richard S. McGowan
Haskins Labs., New Haven, CT 06511
One controversy concerning children's speech is whether they coarticulate more, less, or about the same as adults. A confounding factor in studies addressing this issue is that vocal tract morphology varies with age and sex: Ratios of pharyngeal to oral cavity length are smallest for children, largest for men, and intermediate for women. Consequently, differences among men's, women's, and children's F2s should be greater for front unrounded than for back unrounded vowels [G. Fant, Speech Sounds and Features (1973)]. Pharyngeal and oral cavity lengths and F2s for /i/ and /(open aye)/ at vowel center of CV syllables were compared for women and 3-year-olds, with men serving as a reference. Results showed that children's F2s did not differ from those of women as much as would be predicted based on anatomical considerations. This finding was used to evaluate the magnitude of children's anticipatory coarticulation. It was found that F2s of children's /i/ and /(open aye)/ differed more from those of women at voicing onset than at vowel center, suggesting that children were coarticulating more. Two other findings supported this conclusion: (1) Ratios of F2[sub i] to F2[sub (open aye)] were more similar for children at voicing onset and at vowel center than they were for women at these two locations; and (2) ratios of F2 at voicing onset to F2 at vowel center for a given vowel were closer to 1.00 for children than for women. [Work supported by NIH.]