Tutorial: Diagnosing childhood apraxia of speech in Cantonese speakers with quantitative data

Chun Ho Wong, Min Ney Wong, Shelley L. Velleman

Research output: Unpublished conference presentation (presented paper, abstract, poster)Conference presentation (not published in journal/proceeding/book)Academic researchpeer-review


Childhood apraxia of speech (CAS), a type of pediatric motor speech disorder, is characterized by speech sound and prosodic errors, which result from impaired speech motor planning and programming skills. Wong et al. (2021) recently reported a diagnostic approach for Cantonese speakers with CAS, which was modified from Murray et al. (2015). The approach requires conversion of perceptual judgments to quantitative data. CAS diagnoses were confirmed according to the pre-set quantitative criteria. The purpose of this tutorial is to describe the diagnostic process for Cantonese speakers with suspected CAS in detail, in order to demonstrate to clinicians how to apply the diagnostic approach.

Two boys and two girls, aged between 3;7 to 5;9 (mean = 4.83 years; SD = 0.97), participated in this study. All participants received a 2-hour assessment from the first author.

Five clinical features (i.e., token-to-token inconsistent errors [IE], lengthened and disrupted coarticulatory transitions between sounds and syllables [LDCT], lexical tone errors [LTE], reduced accuracy in multisyllabic words [RA], and reduced phone accuracy on DDK tasks [RPA]) were required to be observed in four different assessment tasks (i.e., speech sample, standardized single-word articulation test [i.e., HKCAT], DDK task, and imitation of polysyllabic words [IPW]). Each of the fifty items on the HKCAT was given to the children twice consecutively. The IPW task includes 43 trisyllabic words, ten 4-syllable words, ten 5-syllable words, and 14 phrases. The children imitated each item three times consecutively to determine the consistency score (CS). One point of CS was given separately for each consistent segmental and tone production. Percentage of phonemes/phones correct (PPC) and percentage of tone correct (PTC) were calculated based on all of the productions from both tasks. The DDK task required the children to produce [pha1], [tha1], [kha1], [pha1tha1kha1], and /phau2thin1khiu4/ (meaning “running on the bridge”) as fast as possible with as many repetitions as possible within one breath. PPC was calculated based on all of these productions. The clinical features were confirmed using quantitative criteria: IE are confirmed with <60% CS on both the HKCAT and IPW task; LTE are confirmed with <100 PTC on both the HKCAT and IPW task; RA is confirmed with <60% PPC on the HKCAT and IPW task; and RPA is confirmed with <70% PPC on DDK tasks.

All of the children met the quantitative criteria and diagnostic criteria proposed by Wong et al. (2021). All children showed reduced CS on the HKCAT (M = 46.5%; SD = 10.2%) and IPW tasks (M = 14.3%; SD = 9.3%); reduced PTC on the HKCAT (M = 53.3%; SD = 32.3%) and IPW tasks (M = 45.2%; SD = 31.8%); and reduced PPC on the HKCAT (M = 36.7%; SD = 24.6%), IPW (M = 37.4%; SD = 19.7%), and DDK tasks (M = 26.2%; SD = 17.0%).

Learning outcomes
The participants will be able to 1) describe appropriate assessment tasks and diagnostic criteria for CAS in Cantonese speakers, and 2) describe quantitative reference data for each measure on the different tasks.


Murray, E., McCabe, P., Heard, R., & Ballard, K. (2015). Differential diagnosis of children with suspected childhood apraxia of speech. Journal of Speech, Language, and Hearing Research, 58(1), 43-60. https://doi.org/doi:10.1044/2014_JSLHR-S-12-0358

Wong, E. C. H., Velleman, S. L., Tong, M. C. F., & Lee, K. Y. S. (2021). Pitch variation in children with childhood apraxia of speech: Preliminary findings. American Journal of Speech-Language Pathology, 30(3S), 1511-1524. https://doi.org/10.1044/2021_AJSLP-20-00150

Original languageEnglish
Publication statusNot published / presented only - 29 Oct 2022
EventAPSSLH Online Symposium 2022 - Online
Duration: 29 Oct 202230 Oct 2022


Forum/SymposiumAPSSLH Online Symposium 2022
Internet address


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