Purpose: The purpose of the study was to investigate vowel-specific intelligibility and acoustic patterns of individuals with different severities of dysarthria secondary to amyotrophic lateral sclerosis (ALS). Method: Twenty-three individuals with dysarthria secondary to ALS and 22 typically aging individuals participated as speakers.…

Covert contrast is the statistically reliable distinction between target language phonemes produced in the process of language acquisition that is nevertheless not perceived by a native speaker of that language. This paper examines the acquisition of contrasts in four Najdi Arabic fricatives, /s/, /[voiceless palato-alveolar fricative]/,…

Purpose: This study has two key aims--first, to provide developmental articulatory norms for the alveolar-velar distinction in 30 English-speaking typically developing (TD) children; second, to illustrate the utility of the reported measures for classifying and quantifying the speech of children with a history of persistent velar fronting as they…

Purpose: The aim of this study was to determine the relation of tongue--jaw coupling to phonetic distinctiveness of vowels in persons at different stages (i.e., early, middle, late) of bulbar motor involvement in amyotrophic lateral sclerosis (ALS) and healthy controls. Method: The pattern of spatial tongue-jaw coupling was derived from 11…

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: Poor nonword repetition accuracy is a hallmark of children with developmental language disorder (DLD). However, other diagnostic categories also show impaired nonword repetition performance relative to children with typical development (TD); therefore, this task is currently a sensitive but nonspecific index of DLD. In this study, we…

Purpose: This study compared performance on the Syllable Repetition Task (SRT) by preschoolers with diverse speech and language abilities to identify underlying impairments in speech processes. Method: Three groups of 13 children ages 4 and 5 years with (a) typically developing (TD) speech and language, (b) speech sound disorder (SSD), and (c)…

Purpose: Most acoustic and articulatory studies on /l/ have focused on either duration, formant frequencies, or tongue shape during the constriction interval. Only a limited set of data exists for the transition characteristics of /l/ to and from surrounding vowels. The aim of this study was to examine second formant (F2) transition…

Purpose: This study aimed to improve understanding of speech characteristics associated with dysarthria in children with cerebral palsy by analyzing segmental and global formant measures in single-word and sentence contexts. Method: Ten 5-year-old children with cerebral palsy and dysarthria and 10 age-matched, typically developing children…

Introduction: The current work presents a framework of motoric complexity where stimuli differ according to movement elements across a sound sequence (i.e., consonant transitions and vowel direction). This framework was then examined in children with childhood apraxia of speech (CAS), other speech sound disorders (SSDs), and typical development…

Purpose: The authors investigated how different variants of clear speech affect segmental and suprasegmental acoustic measures of speech in speakers with Parkinson's disease and a healthy control group. Method: A total of 14 participants with Parkinson's disease and 14 control participants served as speakers. Each speaker produced 18 different…

Purpose: This study was designed to test two hypotheses about apraxia of speech (AOS) derived from the Directions Into Velocities of Articulators (DIVA) model (Guenther et al., 2006): the feedforward system deficit hypothesis and the feedback system deficit hypothesis. Method: The authors used noise masking to minimize auditory feedback during…

Children with dysarthria due to cerebral palsy (CP) present with decreased vowel space area and reduced word intelligibility. Although a robust relationship exists between vowel space and word intelligibility, little is known about the intelligibility of vowels in this population. This exploratory study investigated the intelligibility of American…

This study reported adult scores on two measures of tongue shape, based on midsagittal tongue shape data from ultrasound imaging. One of the measures quantified the extent of tongue dorsum excursion, and the other measure represented the place of maximal excursion. Data from six adult speakers of Scottish Standard English without speech disorders…

Purpose: The purpose of this study was to describe normative and validation data on the Intelligibility in Context Scale (ICS; McLeod, Harrison, & McCormack, 2012c) for English-speaking children. Method: The ICS is a 7-item, parent-report measure of children's speech intelligibility with a range of communicative partners. Data were collected…