Profiles of vocalization change in children with autism receiving early intervention

Abstract

Children with autism spectrum disorder (ASD) commonly present with comorbid language impairment, negatively impacting their learning and participation across settings. Addressing these needs requires a detailed understanding of their communication trajectories. In this study, we used the language environment and analysis (LENA) system to examine possible changes in children's (a) vocalizations and (b) ratio of speech to nonspeech vocalizations over a 10-month period. Data for 23 children with ASD (17M, 6F; ages 32-67 months) were analyzed, including monthly 3-hr in-class recordings and standardized measures of language, cognition, and ASD characteristics. Using hierarchical generalized linear models, we found significant time-trends for child vocalizations (P ≤ 0.001) and the vocalization ratio (P = 0.02), reflecting a waxing and waning pattern. Children with higher expressive language scores (Mullen scales of early learning, Vineland adaptive behavior scales -2nd Ed.) and nonverbal cognition (Mullen scales of early learning), and fewer ASD characteristics (social communication questionnaire) demonstrated greater increases in the vocalization ratio over time (P values 0.04-0.01). Children with greater language and cognition difficulties were the most vocal, but produced a higher proportion of nonspeech vocalizations. The results demonstrate that significant fluctuations, as opposed to linear increases, may be observed in children with ASD receiving intervention, highlighting the value of assessment at multiple time-points. In addition, the findings highlight the need to consider both the quantity (vocalization counts) and quality (ratio of speech to nonspeech vocalizations) when interpreting LENA data, with the latter appearing to provide a more robust measure of communication. Autism Res 2019, 12: 830-842.Lay Abstract: In this study, we examined possible changes in speech and nonspeech vocalizations in 23 children with autism attending a comprehensive early intervention program over a 10-month period. Contrary to our expectation, we observed a waxing and waning pattern of change in children's vocalizations over time, rather than a steady increase. We also found evidence to suggest that looking at the quality of children's vocalizations (i.e., the ratio of speech to nonspeech vocalizations) provides a more accurate picture of children's development than simply looking at the quantity (i.e., how frequently they vocalize).

Exploring Growth in Expressive Communication of Infants and Toddlers With Autism Spectrum Disorder

“…Although these findings align with prior research related to the language development of children with ASD (Trembath et al, 2019), it is important to note that correlations were only observed between gestures and total communication score and children’s severity of autism symptoms. No significant correlations were found for the other key skills or between the ECI and children’s cognitive ability or gender.…”

Spoken Language Change in Children on the Autism Spectrum Receiving Community-Based Interventions

“…Phonetic inventory-the number of different speech sounds produced-is a core aspect of structural language development in children but impaired in at least some children on the autism spectrum (Saul & Norbury, 2020;Yoder et al, 2015). The ratio of speech to non-speech vocalizations was selected on the conceptual basis that it reflects children's capacity to produce intelligible-and thus easily interpreted-communicative acts, and emerging evidence of a possible association with greater language development among children receiving intervention (e.g., Plumb & Wetherby, 2013;Trembath et al, 2019).…”

Assessing Communication in Children with Autism Spectrum Disorder Who Are Minimally Verbal

“…While a number of authors have identified the potential for LENA to act as a sensitive measure of vocal change in children with ASD, including those who are minimally verbal, there is growing evidence of challenges with reliability and validity, particularly in children with echolalia and in older children approaching (and certainly beyond) the designated age range of 0 to 5 years [33][34][35].…”