Purpose: This study investigated the criterion (analytical and clinical) and construct (divergent) validity of a novel, acoustic-based framework composed of five key components of motor control: Coordination, Consistency, Speed, Precision, and Rate. Method: Acoustic and kinematic analyses were performed on audio recordings from 22 subjects with…

Background: A well-developed proprioceptive system is essential for motor control, muscle tone and voluntary movements. Sound proprioceptive development of young children can positively influence their motor abilities, while adequate movement abilities consequently form a strong foundation for young children entering the formal school setting.…

Neuroimaging has revealed a core network of cortical regions that contribute to speech production, but the functional organization of this network remains poorly understood. Purpose: We describe efforts to identify reliable boundaries around functionally homogenous regions within the cortical speech motor control network in order to improve the…

Purpose: This study examined the speech acoustic characteristics of Jamaican Creole (JC) and English in bilingual preschoolers and adults using acoustic duration measures. The aims were to determine if, for JC and English, (a) child and adult acoustic duration characteristics differ, (b) differences occur in preschoolers' duration patterns based…

Purpose: Atypical vowel production contributes to reduced speech intelligibility in children and adults with Down syndrome (DS). This study compares the acoustic data of the corner vowels /i/, /u/, /ae/, and /[open back unrounded vowel]/ from speakers with DS against typically developing/developed (TD) speakers. Method: Measurements of the…

Purpose: Developmental coordination disorder (DCD) is characterized by poor coordination and clumsiness in children. Subjects often show unsteady gait, frequent tripping, and difficulty holding objects. Here we evaluated the implicit and explicit motor learning capabilities of children with DCD. Method: We assessed a total of 80 children…

Two studies were conducted of students with and without persisting Specific Learning Disabilities (SLDs-WL) in Grades 4 to 9 (M = 11 years, 11 months) that supported the hypotheses that CELF 4 parent ratings for listening (language by ear), speaking (language by mouth), reading (language by eye), and writing (language by hand) were correlated with…

Purpose: This exploratory study aims to investigate variations in voice production in the presence of background noise (Lombard effect) in individuals with nonphonotraumatic vocal hyperfunction (NPVH) and individuals with typical voices using acoustic, aerodynamic, and vocal fold vibratory measures of phonatory function. Method: Nineteen…

Purpose: Speech production deficits and reduced intelligibility are frequently noted in individuals with Down syndrome (DS) and are attributed to a combination of several factors. This study reports acoustic data on vowel production in young adults with DS and relates these findings to perceptual analysis of speech intelligibility. Method:…

Purpose: Speech motor control relies on neural processes for generating sensory expectations using an efference copy mechanism to maintain accurate productions. The N100 auditory event-related potential (ERP) has been identified as a possible neural marker of the efference copy with a reduced amplitude during active listening while speaking when…

Increased intrasubject variability (ISV), or short-term, within-person fluctuations in behavioral performance is consistently found in Attention-Deficit/Hyperactivity Disorder (ADHD). ADHD is also associated with impairments in motor control, particularly in boys. The results of the few studies that have examined variability in self-generated…

Purpose: Individuals with cerebellar ataxia (CA) caused by cerebellar degeneration exhibit larger reactive compensatory responses to unexpected auditory feedback perturbations than neurobiologically typical speakers, suggesting they may rely more on feedback control during speech. We test this hypothesis by examining variability in unaltered…

Objective: We aimed to investigate the production of contrastive emphasis in French-speaking 4-year-olds and adults. Based on previous work, we predicted that, due to their immature motor control abilities, preschool-aged children would produce smaller articulatory differences between emphasized and neutral syllables than adults. Method: Ten…

Purpose: The author presents a view of research in speech motor control over the past 5 decades, as observed from within Ken Stevens's Speech Communication Group (SCG) in the Research Laboratory of Electronics at MIT. Method: The author presents a limited overview of some important developments and discoveries. The perspective is based…

Purpose: The purpose of this study was to investigate executive control in adults who stutter (AWS) and adults who do not stutter (AWNS) via a nonspeech paradigm, wherein eye movements were monitored (i.e., antisaccade task). Processes involved in an antisaccade task include working memory, attention, and voluntary motor control, but the task…