Relating Acoustic Measures to Listener Ratings of Children's Productions of Word-Initial /(sic)/ and /w/

Purpose: The /(sic)/ productions of young children acquiring American English are highly variable and often inaccurate, with [w] as the most common substitution error. One acoustic indicator of the goodness of children's /(sic)/ productions is the difference between the frequency of the second formant (F2) and the third for-mant (F3), with a smaller F3-F2 difference being associated with a perceptually more adultlike /(sic)/. This study analyzed the effectiveness of automatically extracted F3-F2 differences in characterizing young children's productions of /(sic)/-/w/ in comparison with manually coded measurements. Method: Automated F3-F2 differences were extracted from productions of a variety of different /(sic)/-and /w/-initial words spoken by 3-to 4-year-old monolin-gual preschoolers (N = 117; 2,278 tokens in total). These automated measures were compared to ratings of the phoneme goodness of children's productions as rated by untrained adult listeners (n = 132) on a visual analog scale, as well as to narrow transcriptions of the production into four categories: [(sic)], [w], and two intermediate categories. Results: Data visualizations show a weak relationship between automated F3-F2 differences with listener ratings and narrow transcriptions. Mixed-effects models suggest the automated F3-F2 difference only modestly predicts listener ratings (R-2 = .37) and narrow transcriptions (R-2 = .32). Conclusion: The weak relationship between automated F3-F2 difference and both listener ratings and narrow transcriptions suggests that these automated acoustic measures are of questionable reliability and utility in assessing pre-school children's mastery of the /(sic)/-/w/ contrast.