JCPSLP Vol 23 Issue 2 2021

Notes 1 In the original study, this group was termed specific language impairment (SLI), but we now use the updated term developmental language disorder (DLD) as per current SPA guidelines and Bishop et al. (2017). References Ambrose, S. E., Thomas, A., & Moeller, M. P. (2016). Assessing vocal development in infants and toddlers who are hard of hearing: A parent-report tool. The Journal of Deaf Studies and Deaf Education , 21 (3), 237–248. doi:10.1093/deafed/enw027 Aziz, A. A., Shohdi, S., Osman, D. M., & Habib, E. I. (2010). Childhood apraxia of speech and multiple phonological disorders in Cairo-Egyptian Arabic speaking children: Language, speech, and oro-motor differences. International Journal of Pediatric Otorhinolaryngology , 74 (6), 578–585. doi:https://doi.org/10.1016/j.ijporl.2010.02.003 Brisson, J., Martel, K., Serres, J., Sirois, S., & Adrien, J.-L. (2014). Acoustic analysis of oral productions of infants later diagnosed with autism and their mother. Infant Mental Health Journal , 35 (3), 285–295. doi:https://doi. org/10.1002/imhj.21442 Brumbaugh, K. M., & Smit, A. B. (2013). Treating children ages 3–6 who have speech sound disorder: a survey. Language, Speech & Hearing Services in Schools , 44 (3), 306–319. doi:http://dx.doi.org/10.1044/0161- 1461(2013/12-0029) Bishop, D. V. M., Snowling, M. J., Thompson, P. A., & Greenhalgh, T. (2017). Phase 2 of CATALISE: a multinational and multidisciplinary Delphi consensus study of problems with language development: Terminology. Journal of Child Psychology and Psychiatry , 58 (10), 1068–1080. doi:10.1111/jcpp.12721 Dodd, B. (2005). Children with speech disorder: Defining the problem. In B. Dodd’s (Ed.), Differential diagnosis and treatment of children with speech disorder (2nd ed., pp. 3–23). Whurr Publishers. Davis, B. L., & Velleman, S. L. (2000). Differential diagnosis and treatment of developmental apraxia of speech in infants and toddlers. Infant-Toddler Intervention , 10 (3), 177–192. Eadie, P., Morgan, A., Ukoumunne, O. C., Ttofari Eecen, K., Wake, M., & Reilly, S. (2015). Speech sound disorder at 4 years: Prevalence, comorbidities, and predictors in a community cohort of children. Developmental Medicine & Child Neurology , 57 (6), 578–584. Eilers, R. E., Neal, R. A., & Oller, K. D. (1996). Late onset babbling as an early marker of abnormal development. Infant Behavior and Development, 19 (Supplement 1), 439. Highman, C., Hennessey, N., Sherwood, M., & Leitão, S. (2008). Retrospective parent report of early vocal behaviours in children with suspected childhood apraxia of speech (sCAS). Child Language Teaching and Therapy , 24 (3), 285–306. doi:10.1177/0265659008096294 Iuzzini-Seigel, J., Hogan, T. P., & Green, J. R. (2017). Speech inconsistency in children with childhood apraxia of speech, language impairment, and speech delay: Depends on the stimuli. Journal of Speech, Language & Hearing Research , 60 (5), 1194–1210. doi:10.1044/2016_ JSLHR-S-15-0184 Joffe, V., & Pring, T. (2008). Children with phonological problems: A survey of clinical practice. International Journal of Language & Communication Disorders , 43 (2), 154–164. Maassen, B. (2002). Issues contrasting adult acquired versus developmental apraxia of speech. Seminars in Speech and Language , 23 (4), 257–266.

support their recall, giving some face validity to the reliability of their recall. It is possible that the children’s current presentation influenced their parents’ reporting of earlier development. Children with severe difficulties, in the case of those with sCAS or DLD, for example, may be more likely to have their parents actively search for delays in their previous history, compared to those who may be only mildly delayed or typically developing. Furthermore, participants in the PD group were not directly assessed for inclusion in the study; we relied on managing SLPs to identify appropriate children. The children identified had no comorbid language difficulties and no evidence of speech motor impairment. Clinicians were asked to use clinical judgement to identify children with mild to moderate phonological delays and exclude any potential children with more disordered speech features (e.g., inconsistency, prosodic anomalies) to ensure no overlap with the other groups. Case summaries to support inclusion typically included standardised phonology assessments. The representativeness of the results to children with severe phonological impairment, however, is not clear. Future studies should directly assess children and include those with a range of severities and presentations, ideally using prospective study designs. Clinical implications Clinicians frequently enquire about early development as part of a thorough case history and assessment process (McLeod & Baker, 2017). The present study supports the importance of this and the relevance of obtaining detailed information about prelinguistic vocalisations in planning individualised treatment programs for children with speech disorders. The results suggest different early presentations of children with motor speech disorders and those with phonological delays, and further support the importance of differentiated treatment approaches targeting the underlying deficits (Murray et al., 2014). The findings also highlight the importance of asking questions about general and motor milestones beyond communication as part of the process to collect data to inform differential diagnosis. Conclusions This study extended the findings relating to parent report of prelinguistic vocalisation behaviours of children with sCAS or DLD (Highman et al., 2008) to include a group commonly serviced by speech-language pathologists–children with phonological delay (PD). On many measures, the PD group were reported similarly to the TD group, suggesting that early vocal behaviours in this clinical group do not diverge significantly from typical development, or that parents report this to be the case. In contrast, the results strengthen the findings of both retrospective parent report (Aziz et al., 2010; Highman et al., 2008) and analysis of retrospective home videos (Overby et al., 2020; Overby & Caspari, 2015) of children with CAS, suggesting that a lack of babbling during infancy and delayed emergence of two word combinations are associated with speech motor based disorders such as childhood apraxia of speech. Acknowledgements We are grateful to the SLPs who assisted with recruitment for this study, especially Stacy Fietz who recruited the bulk of participants. Thank you to the parents who so enthusiastically reported on their child’s early development.

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JCPSLP Volume 23, Number 2 2021

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