The Complex Role of Utterance Length on Grammaticality: Multivariate Multilevel Analysis of English and Spanish Utterances of First-Grade English Learners

Purpose: This study examined the relationship between utterance length, syntactic complexity, and the probability of making an error at the utterance level. Method: The participants in this study included 830 Spanish-speaking first graders who were learning English at school. Story retells in both Spanish and English were collected from all children. Generalized mixed linear models were used to examine within-child and between-children effects of utterance length and subordination on the probability of making an error at the utterance level. Results: The relationship between utterance length and grammaticality was found to differ by error type (omission vs. commission), language (Spanish vs. English), and level of analysis (within-child vs. between-children). For errors of commission, the probability of making an error increased as a child produced utterances that were longer relative to their average utterance length (within-child effect). Contrastively, for errors of omission, the probability of making an error decreased when a child produced utterances that were longer relative to their average utterance length (within-child effect). In English, a child who produced utterances that were, on average, longer than the average utterance length for all children produced more errors of commission and fewer errors of omission (between-children effect). This between-children effect was similar in Spanish for errors of commission but nonsignificant for errors of omission. For both error types, the within-child effects of utterance length were moderated by the use of subordination. Conclusion: The relationship between utterance length and grammaticality is complex and varies by error type, language, and whether the frame of reference is the child's own language (within-child effect) or the language of other children (between-children effect). Supplemental Material https://doi.org/10.23641/asha.17035916

Speech Development Between 30 and 119 Months in Typical Children II: Articulation Rate Growth Curves

Purpose We aimed to develop normative growth curves for articulation rate during sentence repetition for typically developing children. Our primary goal was the development of quantile/percentile growth curves so that typical variation in articulation rate with age could be estimated. We also estimated when children became adultlike in their articulation rate, and we examined the contributions of age and utterance length to articulation rate. Method This cross-sectional study involved collection of in-person speech samples from 570 typically developing children (297 girls; 273 boys) who passed speech, language, and hearing screening measures. Pauses greater than 150 ms in duration were removed from the samples, and articulation rate was measured in syllables per second (sps). Results Articulation rate reliably increased with age and utterance length. Rate in all key percentiles increased with age. The median rate (50th percentile) increased from 2.7 sps at 36 months to 3.3 sps at 96 months. The 5th percentile increased from 2.3 to 3.1 sps over the same age range. Using 3.2 sps as a benchmark for adultlike speech, we found the 25th, 50th, and 75th percentiles reached adultlike rates at 99, 75, and 53 months, respectively. Conclusions Articulation rate increases from early childhood into middle childhood, and it is generally adultlike by 10 years of age. Variability in articulation rate among typical children was substantial. Implications for prior research and for clinical usage are discussed.

Speech development between 30 and 119 months in typical children II: Articulation rate growth curves

Purpose: We aimed to develop normative growth curves for articulation rate during sentence repetition for typically developing children. Our primary goal was the development of quantile/percentile growth curves, so that typical variation in articulation rate with age could be estimated. We also estimated when children became adultlike in their articulation rate and we examined the contributions of age and utterance length to articulation rate.Method: This cross-sectional study involved collection of in-person speech samples from 570 typically developing children (297 girls; 273 boys) who passed speech, language, and hearing screening measures. Pauses greater than 150 ms in duration were removed from the samples, and articulation rate was measured in syllables per second (sps).Results: Articulation rate reliably increased with age and utterance length. Rate in all key percentiles increased with age. The median rate (50th percentile) increased from 2.7 sps at 36 months to 3.3 sps at 96 months. The 5th percentile increased from 2.3 to 3.1 sps over the same age range. Using 3.2 sps as a benchmark for adultlike speech, we found the 25th, 50th, and 75th percentiles reached adultlike rates at 99, 75, and 53 months, respectively.Conclusions: Articulation rate increases from early childhood into middle childhood, and it is generally adultlike by 10 years of age. Variability in articulation rate among typical children was substantial. Implications for prior research and for clinical usage are discussed.

A Vocabulary Acquisition and Usage for Late Talkers Treatment Efficacy Study: The Effect of Input Utterance Length and Identification of Responder Profiles

Purpose This study examined the efficacy of the Vocabulary Acquisition and Usage for Late Talkers (VAULT) treatment in a version that manipulated the length of clinician utterance in which a target word was presented (dose length). The study also explored ways to characterize treatment responders versus nonresponders. Method Nineteen primarily English-speaking late-talking toddlers (aged 24–34 months at treatment onset) received VAULT and were quasirandomly assigned to have target words presented in grammatical utterances matching one of two lengths: brief (four words or fewer) or extended (five words or more). Children were measured on their pre- and posttreatment production of (a) target and control words specific to treatment and (b) words not specific to treatment. Classification and Regression Tree (CART) analysis was used to classify responders versus nonresponders. Results VAULT was successful as a whole (i.e., treatment effect sizes of greater than 0), with no difference between the brief and extended conditions. Despite the overall significant treatment effect, the treatment was not successful for all participants. CART results (using participants from the current study and a previous iteration of VAULT) provided a dual-node decision tree for classifying treatment responders versus nonresponders. Conclusions The input-based VAULT treatment protocol is efficacious and offers some flexibility in terms of utterance length. When VAULT works, it works well. The CART decision tree uses pretreatment vocabulary levels and performance in the first two treatment sessions to provide clinicians with promising guidelines for who is likely to be a nonresponder and thus might need a modified treatment plan. Supplemental Material https://doi.org/10.23641/asha.14226641

Speakers construct reference based on listeners’ expected visual search

A foundational assumption of human communication is that speakers ought to say as much as necessary, but no more. How speakers determine what is necessary in a given context, however, is unclear. In studies of referential communication, this expectation is often formalized as the idea that speakers should construct reference by selecting the shortest, sufficiently informative, description. Here we propose that reference production is, instead, a process whereby speakers adopt listeners’ perspectives to facilitate their visual search, without concern for utterance length. We show that a computational model of our proposal predicts graded acceptability judgments with quantitative accuracy, systematically outperforming brevity models. Our model also explains crosslinguistic differences in speakers’ propensity to over-specify in different visual contexts. Our findings suggest that reference production is best understood as driven by a cooperative goal to help the listener understand the intended message, rather than by an egocentric effort to minimize utterance length.

The ecology of prelinguistic vocal learning: parents simplify the structure of their speech in response to babbling

What is the function of babbling in language learning? We examined the structure of parental speech as a function of contingency on infants’ non-cry prelinguistic vocalizations. We analyzed several acoustic and linguistic measures of caregivers’ speech. Contingent speech was less lexically diverse and shorter in utterance length than non-contingent speech. We also found that the lexical diversity of contingent parental speech only predicted infant vocal maturity. These findings illustrate a new form of influence infants have over their ambient language in everyday learning environments. By vocalizing, infants catalyze the production of simplified, more easily learnable language from caregivers.