Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Feb;22(1):12-23.
doi: 10.1080/17549507.2019.1568571. Epub 2019 Feb 11.

Lexical stress in childhood apraxia of speech: acoustic and kinematic findings

Hailey C Kopera  1 , Maria I Grigos  1
Affiliations

Lexical stress in childhood apraxia of speech: acoustic and kinematic findings

Hailey C Kopera et al. Int J Speech Lang Pathol. 2020 Feb.

Abstract

Purpose: This study investigated the acoustic and articulatory movement parameters underlying lexical stress production in children with apraxia of speech (CAS), children with articulation/phonological delay (i.e. speech delay, SD), and children with typical speech-language development (TD). We examined whether there were group differences in these instrumental measures of stress production.Method: Participants were 24 children (seven CAS, eight SD, nine TD) between three and seven years of age. Acoustic and kinematic measures, including acoustic duration, peak and average fundamental frequency, and jaw movement duration and displacement, were taken from perceptually accurate productions of a strong-weak form. Relative stress analyses were conducted using the Pairwise Variability Index (PVI).Result: There was a significant difference between the CAS and TD groups in the PVI for movement duration, with the CAS group showing a smaller movement duration contrast between stressed and unstressed syllables. There were no significant group differences for displacement or any of the acoustic variables.Conclusion: The kinematic findings suggest reduced temporal control for lexical stress production in children with CAS. This finding surfaced during analyses of perceptually accurate productions but suggests a possible basis for lexical stress errors in CAS that could be explored in future studies.

Keywords: Childhood apraxia of speech (CAS); acoustic measures; kinematic measures; lexical stress.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
Kinematic trace of jaw displacement for the utterance puppypop (/ˈpʌ.pi.ˌpap/). Movement duration was calculated as the time between points A-C and C-E. Displacement was measured as the distance between points A-B and C-D.
Figure 2.
Figure 2.
Boxplots of pairwise variability indices for movement duration by group. PVI = pairwise variability index; CAS = childhood apraxia of speech; SD = speech delay characterised by articulation/phonological impairment; TD = typical development.
See this image and copyright information in PMC

References

    1. American Speech, Language, Hearing Association. (2007). Childhood Apraxia of Speech [Technical Report]. Available from www.ASHA.org/policy.
    1. Bahr RH (2005). Differential diagnosis of severe speech disorders using speech gestures. Topics in Language Disorders, 25, 254–265.
    1. Ballard KJ, Djaja D, Arciuli J, James DGH, & van Doorn J (2012). Developmental trajectory for production of prosody: Lexical stress contrastivity in children ages 3 to 7 years and in adults. Journal of Speech, Language, Hearing Research, 55, 1822–1835. - PubMed
    1. Ballard KJ, Robin DA, McCabe P, & McDonald J (2010). A treatment for dysprosody in childhood apraxia of speech. Journal of Speech, Language, Hearing Research, 53, 1227–1245. - PubMed
    1. Bates D, Maechler M, Bolker B, & Walker S (2015). Fitting linear mixed effects models using lme4. Journal of Statistical Software, 67, 1–48.

Publication types