The present study investigated the effects of lexical age of acquisition (AoA), phonological complexity, age and expressive vocabulary on spoken word variability and accuracy in typically developing infants, aged 1;9-3;1. It was hypothesized that later-acquired words and those with more complex speech sounds would be produced more variably and less accurately than earlier-acquired words and those with less complex speech sounds. It was also hypothesized that word variability would decrease and word accuracy would increase with increasing age and vocabulary knowledge. Participants' productions of 20 target words, experimentally controlled for AoA and phonological complexity, were audio-recorded during a play session. Results revealed a nonsignificant effect of AoA on variability and accuracy, a significant effect of phonological complexity on variability and accuracy, a significant effect of age on variability and accuracy and a significant effect of vocabulary on variability. Theoretical and clinical implications are discussed.

The purpose of this study was to examine potential concurrent predictors and replicate rates of token-to-token inconsistency (inconsistency in repeated productions of the same word) in 43 children with typical speech-language development, ages 2;6 to 4;2. A standard linear regression was used to determine which variables, if any, among age, expressive and receptive vocabulary, and speech sound production abilities predicted token-to-token inconsistency. Inconsistency rates in children from one research site, reported elsewhere, were compared to rates in children from a second research site. The results revealed that expressive vocabulary was the only significant predictor of token-to-token inconsistency in these children. Furthermore, inconsistency rates were similarly high across the two research sites. The findings are discussed in terms of their implications for our theoretical understanding of token-to-token inconsistency and its role in the differential diagnosis of speech sound disorders in children.

Aim:The purpose of this study was to examine the effects of an integrated phoneme awareness/ speech intervention in comparison to an alternating speech/morphosyntax intervention for specific areas targeted by the different interventions, as well as the extent of indirect gains in nontargeted areas. Method: A total of 30 children with co-occurring speech sound disorder and language impairment, average age 4;5, participated in the study, 18 from the United States and 12 from New Zealand. Children from matched pairs were randomly assigned to the 2 proven efficacious treatments, which were delivered in 6-week blocks separated by a 6-week break. Phoneme awareness, speech sound production, and oral language outcome measures were collected pretreatment and after each intervention block. Results and Conclusions: Both intervention groups made statistically significant gains in all measures, with the exception of a morpheme measure only approaching significance. There were clear trends in favor of the specificity of the interventions suggesting increased sample size might have led to some significant intervention differences. Results further implicate the need for early intervention that integrates oral language and phoneme awareness/early literacy skills for children with multiple deficits.