Perceptual characteristics in AOS and aphasia (Bislick & Hula, 2019)

Abstract

Purpose: This retrospective analysis examined group differences in error rate across 4 contextual variables (clusters vs. singletons, syllable position, number of syllables, and articulatory phonetic features) in adults with apraxia of speech (AOS) and adults with aphasia only. Group differences in the distribution of error type across contextual variables were also examined.Method: Ten individuals with acquired AOS and aphasia and 11 individuals with aphasia participated in this study. In the context of a 2-group experimental design, the influence of 4 contextual variables on error rate and error type distribution was examined via repetition of 29 multisyllabic words. Error rates were analyzed using Bayesian methods, whereas distribution of error type was examined via descriptive statistics.Results: There were 4 findings of robust differences between the 2 groups. These differences were found for syllable position, number of syllables, manner of articulation, and voicing. Group differences were less robust for clusters versus singletons and place of articulation. Results of error type distribution show a high proportion of distortion and substitution errors in speakers with AOS and a high proportion of substitution and omission errors in speakers with aphasia.Conclusion: Findings add to the continued effort to improve the understanding and assessment of AOS and aphasia. Several contextual variables more consistently influenced breakdown in participants with AOS compared to participants with aphasia and should be considered during the diagnostic process.Supplemental Material S1. Detailed explanation of statistical models for Research Questions 1–4.Bislick, L., & Hula, W. D. (2019). Perceptual characteristics of consonant production in apraxia of speech and aphasia. American Journal of Speech-Language Pathology, 28(4), 1411–1431. https://doi.org/10.1044/2019_AJSLP-18-0169