Date of Award


Document type


Access Type

Open Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

Degree Program

Communication Disorders

First Advisor

Mary V. Andrianopoulos

Second Advisor

Shelley L. Velleman

Third Advisor

Lisa A. Keller

Subject Categories

Communication Sciences and Disorders


Autism affects 1 in 88 children (Center for Disease Control, 2009), approximately 50% of whom will not develop speech (Seal & Bonvillian, 1997). Some researchers hypothesize that these difficulties in developing oral speech reflect underlying motor speech deficits (Prizant, 1996; Seal & Bonvillian, 1997; Szypulski, 2003; Andrianopoulos, Boucher, Velleman & colleagues 2007-2010). This investigation sought to identify the presence or absence of specific motor speech markers in ASD through an innovative best-practice protocol for assessing the speech, prosody, and voice quality of individuals with ASD.

The study focused on apraxic-like motor planning/programming features and dysarthric-like motor execution features in imitated, elicited, and spontaneous speech in 15 children with ASD between 4;0 and 12;11 years as compared to 15 children who were NTD.

Speech analyses included imitated speech tasks for [f] and [a] prolongation, the short phrase "pea tea key" and AMRs and SMRs; elicited speech tasks for Counting 1-10 and singing Happy Birthday; along with spontaneous speech tasks for telling two stories based on wordless picture stories and discussing a topic of interest.

Results indicated that children with ASD presented with significantly decreased Maximum Phonation Times; lower formant values; lower pitch values; decreased rate of speech characterized by increased utterance, pause and vowel durations; reduced number of syllable repetitions in AMR and SMR tasks; variable and/or inconsistent performance across tasks; and a mildly deviant voice, further characterized by mildly deviant levels of roughness and strain, atypical production of prosody and inconsistent nasality.

Based on the results of this empirical investigation, an acoustic-perceptual and motor speech profile for a sample population of children with an autism spectrum disorder can be determined by six tasks: prolongation of [f] and [a], articulation of AMRs and SMRs, Counting 1-10, and telling a story based on a wordless picture book. These objective measures can empirically determine the presence, prevalence, and nature of speech, phonatory, and prosodic deficits in this sample population. They support that intervention for children with ASD should not only focus on pragmatics, MLU, and vocabulary, as is often the case. Rather, voice and motor speech intervention protocols should be incorporated as appropriate to individuals with autism.