Apraxia of Speech: A Perceptual and VOT Analysis of Stop Consonants

J Wambaugh, C Nessler, S Mauszycki, J Bennett


This investigation was designed to examine the effects of 1) method of stimuli presentation and 2) sampling over time on production of stop consonants with a speaker with acquired apraxia of speech. Stimuli were presented in a blocked format and a randomized format on three sampling occasions and number of perceived errors, types of errors, consistency of errors, and VOTs were evaluated. Results indicated that errors were predictable in both conditions, but that more variability in error type occurred in the randomized condition.  Error location was more consistent between the first and second sampling occasions (separated by one day) than between the first and third occasions (separated by one week).  Within presentation condition, VOT values did not differ significantly across sampling times. However, VOT values were significantly different across sampling conditions.