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: Down syndrome occurs in one of 700 births, and high rates of hearing loss are reported in this population. This puts children with Down syndrome at risk for communication, learning, and social development difficulties, compounding known language and cognitive vulnerabilities in this population. The purpose of this study was to…

Purpose: The current study addresses a gap in the literature regarding syntactic development of adolescent boys with fragile X syndrome (FXS) and Down syndrome (DS). Specifically, we ask whether syntactic skills plateau or continue to change during adolescence for these groups and whether the profile of syntactic change differs between boys with…

Purpose: Aided augmentative and alternative communication (AAC) displays are often designed as symmetrical row--column grids, with each square in the grid containing a symbol. To maximize vocabulary on displays, symbols are often placed close to one another, and background color cuing is used to signal/differentiate symbols across different…

Purpose: Toddlers with Down syndrome (DS) showcase comparable or higher rates of gestures than chronological age-- and language-matched toddlers without DS. Little is known about how gesture use in toddlers with DS relates to multiple domains of development, including motor, pragmatics, language, and visual reception (VR) skills. Unexplored is…

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: This study examined the effects of an intensive voice treatment Lee Silverman Voice Treatment (LSVT LOUD) on children with Down syndrome (DS) and motor speech disorders. Method: A Phase I, multiple baseline, single-subject design with replication across nine participants with DS was used. Single-word intelligibility, acoustic measures of…

Purpose: The aims of this study were to investigate the occurrence of stuttering behavior across time and to evaluate the relationship between stuttering behavior and language ability in children with Down syndrome. Method: A national age cohort of Norwegian first graders with Down syndrome (N = 75) participated in the study. Speech samples from a…

Purpose: The study explored longitudinally the course of vocabulary and general language development in a group of infants with Down syndrome (DS) compared to a group of typically developing (TD) infants matched on nonverbal mental ability (NVMA). Method: We compared the vocabulary and general language trajectories of the two groups in two ways:…

Purpose: This work evaluates whether seeing the speaker's face could improve the speech intelligibility of adults with Down syndrome (DS). This is not straightforward because DS induces a number of anatomical and motor anomalies affecting the orofacial zone. Method: A speech-in-noise perception test was used to evaluate the intelligibility of 16…

Purpose: The aim of this study was to determine how the speech disorder profiles in Down syndrome (DS) relate to reduced intelligibility, atypical overall quality, and impairments in the subsystems of speech production (phonation, articulation, resonance, and prosody). Method: Auditory-perceptual ratings of intelligibility, overall quality, and…

Purpose: Many aided augmentative and alternative communication (AAC) systems require the use of an external display that is represented via a visual modality. It is critical to evaluate and understand visual-perceptual processing in individuals with disabilities who could benefit from AAC. One way to evaluate how individuals process visual…

Purpose: There is an ongoing need to develop assessments of spontaneous speech that focus on whether the child's utterances are comprehensible to listeners. This study sought to identify the attributes of a stable ratings-based measure of speech comprehensibility, which enabled examining the criterion-related validity of an orthography-based…

Purpose: The ability to repair breakdowns in communication is an important pragmatic language skill that helps to maintain clear and meaningful interactions. Examining this ability in genetically based neurodevelopmental disabilities in which pragmatics are affected can provide important information about the precise pragmatic skills impacted…

Purpose: The study aims to explore whether finite verbal morphology is affected in children/adolescents with Down syndrome (DS), whether observed deficits in this domain are indicative of a delayed or deviant development, and whether they are due to phonetic/phonological problems or deficits in phonological short-term memory. Method: An…