Special Education and Communication Disorders Faculty Publications Copyright (c) 2013 University of Nebraska - Lincoln All rights reserved. http://digitalcommons.unl.edu/specedfacpub Recent documents in Special Education and Communication Disorders Faculty Publications en-us Sun, 12 May 2013 01:35:52 PDT 3600 Tongue Movements and Their Acoustic Consequences in Amyotrophic Lateral Sclerosis http://digitalcommons.unl.edu/specedfacpub/83 http://digitalcommons.unl.edu/specedfacpub/83 Fri, 10 May 2013 10:33:51 PDT Objective: The relations between acoustic measures and their articulatory bases have rarely been tested in dysarthria but are important for diagnostic and treatment purposes. We tested the association between acoustic measures of F2 range and F2 slope with kinematic measures of tongue movement displacement and speed in individuals with amyotrophic lateral sclerosis (ALS) and healthy controls speaking at normal and slow rates. Relations between acoustic and kinematic measures and speech intelligibility were examined.

Results: As healthy controls reduced their speaking rate, their F2 slopes and movement speeds decreased. In talkers with ALS, acoustic and kinematic variables were associated with changes in speaking rate, characteristic of disease progression. Participants with slow rate had shallower F2 slopes and slower movement speeds than those with normal rate. Relations between F2 range and tongue displacement were weaker. F2 slope, displacement, and duration were correlated with speech intelligibility most consistently.

Conclusion: Findings suggested that F2 slope is a useful marker for tracking disease progression in ALS. F2 slope reflects changes in tongue function with disease progression and is linked to speech intelligibility. Changes in movement speed, however, might be the earliest sign of disease in the tongue.

]]> Yana Yunusova et al. Spatiotemporal Coupling of the Tongue in Amyotrophic Lateral Sclerosis http://digitalcommons.unl.edu/specedfacpub/82 http://digitalcommons.unl.edu/specedfacpub/82 Mon, 06 May 2013 12:02:31 PDT Purpose: The primary aim of the investigation was to identify deficits in spatiotemporal coupling between tongue regions in amyotrophic lateral sclerosis (ALS). The relations between disease-related changes in tongue movement patterns and speech intelligibility were also determined.

Methods: The authors recorded word productions from 11 individuals with ALS with mild, moderate, and severe dysarthria using an x-ray microbeam during word productions. A coupling index based on sliding window covariance was used to determine disease-related changes in the coupling between the tongue regions across each word.

Results: The results indicated decreased spatiotemporal coupling of mid-posterior tongue regions and reduced tongue speed in the ALS-moderate subgroup. Changes in the range of tongue coupling relations and speed of movement were highly correlated with speech intelligibility.

Conclusions: These results provide new insights into the loss of lingual motor control due to ALS and suggest that measures of tongue performance may provide useful indicators of bulbar disease severity and progression.

]]> Mili S. Kuruvilla et al. Increases in Cognitive and Linguistic Processing Primarily Account for Increases in Speaking Rate With Age http://digitalcommons.unl.edu/specedfacpub/81 http://digitalcommons.unl.edu/specedfacpub/81 Mon, 06 May 2013 09:48:54 PDT Age-related increases of speaking rate are not fully understood, but have been attributed to gains in biologic factors and learned skills that support speech production. This study investigated developmental changes in speaking rate and articulatory kinematics of participants aged 4 (N = 7), 7 (N = 10), 10 (N = 9), 13 (N = 7), 16 (N = 9) years, and young adults (N = 11) in speaking tasks varying in task demands. Speaking rate increased with age, with decreases in pauses and articulator displacements but not increases in articulator movement speed. Movement speed did not appear to constrain the speaking. Rather, age-related increases in speaking rate are due to gains in cognitive and linguistic processing and speech motor control.

]]> Ignatius S. B. Nip et al. Distinct developmental profiles in typical speech acquisition http://digitalcommons.unl.edu/specedfacpub/80 http://digitalcommons.unl.edu/specedfacpub/80 Wed, 01 May 2013 10:50:00 PDT Three- to five-year-old children produce speech that is characterized by a high level of variability within and across individuals. This variability, which is manifest in speech movements, acoustics, and overt behaviors, can be input to subgroup discovery methods to identify cohesive subgroups of speakers or to reveal distinct developmental pathways or profiles. This investigation characterized three distinct groups of typically developing children and provided normative benchmarks for speech development. These speech development profiles, identified among 63 typically developing preschool-aged speakers (ages 36–59 mo), were derived from the children's performance on multiple measures. These profiles were obtained by submitting to a k-means cluster analysis of 72 measures that composed three levels of speech analysis: behavioral (e.g., task accuracy, percentage of consonants correct), acoustic (e.g., syllable duration, syllable stress), and kinematic (e.g., variability of movements of the upper lip, lower lip, and jaw). Two of the discovered group profiles were distinguished by measures of variability but not by phonemic accuracy; the third group of children was characterized by their relatively low phonemic accuracy but not by an increase in measures of variability. Analyses revealed that of the original 72 measures, 8 key measures were sufficient to best distinguish the 3 profile groups.

]]> Jennell C. Vick et al. Increasing Higher Level Language Skills to Improve Reading Comprehension http://digitalcommons.unl.edu/specedfacpub/79 http://digitalcommons.unl.edu/specedfacpub/79 Fri, 01 Mar 2013 10:08:13 PST Reading comprehension involves two primary processes: (a) decoding printed text and (b) understanding language accessed through the process of decoding. In the early years of reading development, children’s ability to comprehend text is largely constrained by individual differences in decoding printed text; however, once decoding becomes automatized, reading comprehension is largely dependent upon one’s skills in language comprehension (Catts, Hogan, & Adlof, 2005). In recent decades, numerous studies have investigated how children develop decoding skills and how, when these skills do not develop normally, educators can effectively intervene (e.g., Denton & Mathes, 2003; Simmons et al., 2008; Vellutino, Scanlon, Small, & Fanuele, 2006). Beyond decoding, the substantial role that language skills play in the achievement of skilled reading comprehension has largely been ignored. This is surprising, given that skilled reading comprehension is critical for modern life; success in education, productivity in society, and almost all types of employment require rapid and thorough assimilation of information from text. Further, there are children who develop good decoding skills but fail to develop comparable levels of reading comprehension. A profile of good word reading in the presence of poor comprehension affects approximately 10% of school-age children (Nation, 2005; Yuill & Oakhill, 1991) and demonstrates that skills other than decoding are important for successful comprehension. Clearly a focus on the skills that support text comprehension is essential within the teaching of reading (and communication skills more broadly). In this paper, we provide an overview of a large empirical evidence base that shows that the language skills of inferencing, comprehension monitoring, and use of text structure knowledge are critical to successful comprehension. Because these language skills are not reliant on word reading abilities, we chose to focus on how to stimulate them through shared book readings in early childhood.

]]> Tiffany Hogan et al. Is weak oral language associated with poor spelling in school-age children with specific language impairment, dyslexia or both? http://digitalcommons.unl.edu/specedfacpub/78 http://digitalcommons.unl.edu/specedfacpub/78 Fri, 22 Feb 2013 10:56:16 PST The purpose of this study was to test the hypothesis that word reading accuracy, not oral language, is associated with spelling performance in school-age children. We compared fourth grade spelling accuracy in children with specific language impairment (SLI), dyslexia or both (SLI/dyslexia) to their typically developing grade-matched peers. Results of the study revealed that children with SLI performed similarly to their typically developing peers on a single-word spelling task. Alternatively, those with dyslexia and SLI/dyslexia evidenced poor spelling accuracy. Errors made by both those with dyslexia and SLI/dyslexia were characterized by numerous phonologic, orthographic and semantic errors. Cumulative results support the hypothesis that word reading accuracy, not oral language, is associated with spelling performance in typically developing school-age children and their peers with SLI and dyslexia. Findings are provided as further support for the notion that SLI and dyslexia are distinct, yet co-morbid, developmental disorders.

]]> Jillian H. McCarthy et al. Accuracy of perceptual and acoustic methods for the detection of inspiratory loci in spontaneous speech http://digitalcommons.unl.edu/specedfacpub/77 http://digitalcommons.unl.edu/specedfacpub/77 Wed, 30 Jan 2013 09:38:12 PST The present study investigates the accuracy of perceptually and acoustically determined inspiratory loci in spontaneous speech for the purpose of identifying breath groups. Sixteen participants were asked to talk about simple topics in daily life at a comfortable speaking rate and loudness while connected to a pneumotach and audio microphone. The locations of inspiratory loci were determined on the basis of the aerodynamic signal, which served as a reference for loci identified perceptually and acoustically. Signal detection theory was used to evaluate the accuracy of the methods. The results showed that the greatest accuracy in pause detection was achieved (1) perceptually, on the basis of agreement between at least two of three judges, and (2) acoustically, using a pause duration threshold of 300 ms. In general, the perceptually based method was more accurate than was the acoustically based method. Inconsistencies among perceptually determined, acoustically determined, and aerodynamically determined inspiratory loci for spontaneous speech should be weighed in selecting a method of breath group determination.

]]> Yu-Tsai Wang et al. Whole-Word Recognition from Articulatory Movements for Silent Speech Interfaces http://digitalcommons.unl.edu/specedfacpub/76 http://digitalcommons.unl.edu/specedfacpub/76 Wed, 21 Nov 2012 11:46:21 PST Articulation-based silent speech interfaces convert silently produced speech movements into audible words. These systems are still in their experimental stages, but have significant potential for facilitating oral communication in persons with laryngectomy or speech impairments. In this paper, we report the result of a novel, real-time algorithm that recognizes whole-words based on articulatory movements. This approach differs from prior work that has focused primarily on phoneme-level recognition based on articulatory features. On average, our algorithm missed 1.93 words in a sequence of twenty-five words with an average latency of 0.79 seconds for each word prediction using a data set of 5,500 isolated word samples collected from ten speakers. The results demonstrate the effectiveness of our approach and its potential for building a real-time articulation-based silent speech interface for health applications.

]]> Jun Wang et al. Sentence recognition from articulatory movements for silent speech interfaces http://digitalcommons.unl.edu/specedfacpub/75 http://digitalcommons.unl.edu/specedfacpub/75 Tue, 17 Jul 2012 11:55:37 PDT Recent research has demonstrated the potential of using an articulation-based silent speech interface for command-and-control systems. Such an interface converts articulation to words that can then drive a text-to-speech synthesizer. In this paper, we have proposed a novel near-time algorithm to recognize whole-sentences from continuous tongue and lip movements. Our goal is to assist persons who are aphonic or have a severe motor speech impairment to produce functional speech using their tongue and lips. Our algorithm was tested using a functional sentence data set collected from ten speakers (3012 utterances). The average accuracy was 94.89% with an average latency of 3.11 seconds for each sentence prediction. The results indicate the effectiveness of our approach and its potential for building a real-time articulation-based silent speech interface for clinical applications.

]]> Jun Wang et al. Quantifying Articulatory Distinctiveness of Vowels http://digitalcommons.unl.edu/specedfacpub/74 http://digitalcommons.unl.edu/specedfacpub/74 Tue, 17 Jul 2012 11:55:28 PDT The articulatory distinctiveness among vowels has been frequently characterized descriptively based on tongue height and front-back position; however, very few empirical methods have been proposed to characterize vowels based on time-varying articulatory characteristics. Such information is not only needed to improve knowledge about the articulation of vowels but also to determine the contribution of articulatory imprecision to poor speech intelligibility. In this paper, a novel statistical shape analysis was used to derive a vowel space that depicted the quantified articulatory distinctiveness among vowels based on tongue and lip movements. The effectiveness of the approach was supported by vowel classification accuracy of up to 91.7%. The theoretical relevance and clinical implication of the derived vowel space were discussed.

]]> Jun Wang et al. Vowel Recognition from Continuous Articulatory Movements for Speaker-Dependent Applications http://digitalcommons.unl.edu/specedfacpub/73 http://digitalcommons.unl.edu/specedfacpub/73 Mon, 21 May 2012 15:08:43 PDT A novel approach was developed to recognize vowels from continuous tongue and lip movements. Vowels were classified based on movement patterns (rather than on derived articulatory features, e.g., lip opening) using a machine learning approach. Recognition accuracy on a single-speaker dataset was 94.02% with a very short latency. Recognition accuracy was better for high vowels than for low vowels. This finding parallels previous empirical findings on tongue movements during vowels. The recognition algorithm was then used to drive an articulation-to-acoustics synthesizer. The synthesizer recognizes vowels from continuous input stream of tongue and lip movements and plays the corresponding sound samples in near real-time.

]]> Jun Wang et al. Impact of Computerized “Sounding out” on Spelling Performance of a Child Who Uses AAC: A Preliminary Report http://digitalcommons.unl.edu/specedfacpub/72 http://digitalcommons.unl.edu/specedfacpub/72 Wed, 09 May 2012 13:47:35 PDT Spelling is a vital skill for people who rely on augmentative and alternative communication (AAC). The ability to spell words provides an opportunity to create novel and spontaneous communication and increases educational, social, and employment opportunities for children and adults. However, many children and youth who rely on AAC struggle to gain functional spelling skills and written language. The purpose of this preliminary investigation was to develop a strategy to provide auditory letter-sounds using commercially available computer equipment and to evaluate how such a computerized “sounding out” strategy influences spelling accuracy for one child who required AAC support. The spelling accuracy of both consonants and vowels increased during intervention sessions when individual sounds associated with target words were provided compared to the baseline session when individual sounds were not provided. Future directions are discussed.

]]> Jillian H McCarthy et al. A Kinematic Description of the Temporal Characteristics of Jaw Motion for Early Chewing: Preliminary Findings http://digitalcommons.unl.edu/specedfacpub/71 http://digitalcommons.unl.edu/specedfacpub/71 Wed, 09 May 2012 13:23:36 PDT Purpose: The purpose of this investigation was to describe age- and consistency-related changes in the temporal characteristics of chewing in typically developing children between the ages of 4 and 35 months and adults using high-resolution optically based motion capture technology.

Method: Data were collected from 60 participants (48 children, 12 adults) across 5 age ranges (beginners, 7 months, 12 months, 35 months, and adults); each age group included 12 participants. Three different food consistencies were trialed as appropriate. The data were analyzed to assess changes in chewing rate, chewing sequence duration, and estimated number of chewing cycles.

Results: The results revealed both age- and consistency-related changes in chewing rate, sequence duration, and estimated number of chewing cycles, with consistency differences affecting masticatory timing in children as young as 7 months of age. Chewing rate varied as a function of age and consistency, and chewing sequence duration was shorter for adults than for children regardless of consistency type. In addition, the results from the estimated number of chewing cycles measure suggest that chewing effectiveness increased with age; this measure was also dependent on consistency type.

Conclusions: The findings suggest that the different temporal chewing variables follow distinct developmental trajectories and are consistency dependent in children as young as 7 months of age. Clinical implications are detailed.

]]> Erin M. Wilson et al. A novel fixed-target task to determine articulatory speed constraints in persons with amyotrophic lateral sclerosis http://digitalcommons.unl.edu/specedfacpub/70 http://digitalcommons.unl.edu/specedfacpub/70 Wed, 09 May 2012 13:06:15 PDT Purpose: The goal of this study was to determine if talkers with ALS are limited in their ability to increase lower lip and jaw speed at an early stage of the disease when their speaking rate and intelligibility are only minimally or not affected.

Method: A novel metronome paced fixed-target task was used to assess movement speed capacities during lower lip and jaw oscillations in seven talkers with ALS and seven age and gender matched controls.

Results: Lower lip peak speeds were significantly lower in talkers with mild ALS than in healthy talkers suggesting a lower lip speed constraint in talkers with mild ALS. Jaw peak speeds tended to be lower, but jaw displacements tended to be larger in talkers with mild ALS than in healthy talkers. Because greater speeds are typically expected for larger displacements, outcomes also suggest a jaw speed constraint in talkers with mild ALS.

Conclusions: Lower lip and jaw peak speeds may be sensitive measures to identify bulbar motor performance decline at an early stage of the disease when speaking rate and intelligibility are only minimally affected.

Learning Outcomes: The reader will be able to explain two different articulatory strategies to increase speaking rate and understand why fast speech tasks and diadochokinetic pseudo-speech tasks are not suited to assess articulatory speed capacity in healthy and impaired talkers. The reader will also be able to explain how orofacial movement speed capacity can be tested using a fixed-target task and how ALS affects lower lip and jaw speed capacities during the early stages of the disease.

]]> Antje Mefferd et al. The co-emergence of cognition, language, and speech motor control in early development: A longitudinal correlation study http://digitalcommons.unl.edu/specedfacpub/69 http://digitalcommons.unl.edu/specedfacpub/69 Thu, 02 Jun 2011 10:12:18 PDT Although the development of spoken language is dependent on the emergence of cognitive, language, and speech motor skills, knowledge about how these domains interact during the early stages of communication development is currently limited. This exploratory investigation examines the strength of associations between longitudinal changes in articulatory kinematics and development of skills in multiple domains thought to support early communication development. Twenty-four children were investigated every 3 months between the ages of 9 and 21 months. Movements of the upper lip, lower lip, and jaw were transduced using a three-dimensional motion capture system to obtain age-related changes in movement speed and range of movement. Standardized measures of cognition and language from the Battelle Developmental Inventory, 2nd edition and the MacArthur-Bates Communicative Development Inventory were also collected. Significant associations were identified between orofacial kinematic and the standardized measures of language and cognitive skills, even when age served as covariate.
These findings provide preliminary evidence of interactions between cognition, language, and speech motor skills during early communication development. Further work is needed to identify and quantify causal relations among these co-emerging skills.

]]> Ignatius S. B. Nip et al. Development of Chewing in Children From 12 to 48 Months: Longitudinal Study of EMG Patterns http://digitalcommons.unl.edu/specedfacpub/68 http://digitalcommons.unl.edu/specedfacpub/68 Wed, 01 Jun 2011 13:18:25 PDT Developmental changes in the coordinative organization of masticatory muscles were examined longitudinally in four children over 49 experimental sessions spanning the age range of 12–48 mo. Electromyographic (EMG) records were obtained for right and left masseter muscles, right and left temporalis muscles, and the anterior belly of the digastric. Two independent analytic processes were employed, one that relied on identification of onset and offset of muscle activation and a second that used pairwise cross-correlational techniques. The results of these two analyses, which were found to be consistent with each other, demonstrated that the basic chewing pattern of reciprocally activated antagonistic muscle groups is established by 12 mo of age. Nevertheless, chewing efficiency appears to be improved through a variety of changes in the chewing pattern throughout early development. Coupling of activity among the jaw elevator muscles was shown to strengthen with maturation, and the synchrony of onset and offset of these muscles also increased. Coactivation of antagonistic muscles decreased significantly with development. This decrease in antagonistic coactivation and increase in synchrony among jaw elevators, and a parallel decrease in EMG burst duration, were taken as evidence of increased chewing efficiency. No significant differences in the frequency of chewing were found across the ages studied. Additional considerations include the appropriateness of this coordinative infrastructure for other developing oromotor skills, such as speech production. It is suggested that the relatively fixed coordinative framework for chewing exhibited by these children would not be suitable for adaptation to speech movements, which have been shown to rely on a much more variable and adjustable coordinative organization.

]]> Jordan R. Green et al. Algorithmic Estimation of Pauses in Extended Speech Samples of Dysarthric and Typical Speech http://digitalcommons.unl.edu/specedfacpub/67 http://digitalcommons.unl.edu/specedfacpub/67 Wed, 01 Jun 2011 13:04:34 PDT The aim of this study was to evaluate the validity and performance of an algorithm designed to automatically extract pauses and speech timing information from connected speech samples. Speech samples were obtained from 10 people with amyotrophic lateral sclerosis (ALS) and 10 control speakers. Pauses were identified manually and algorithmically from digitally recorded recitations of a speech passage that was developed to improve the precision of pause boundary detection. The manual and algorithmic methods did not yield significantly different results. A stepwise analysis of three different pause detection parameters revealed that estimates of percent pause time were highly dependent on the values specified for the minimum acceptable pause duration and the minimum signal amplitude. Consistent with previous reports of dysarthric speech, pauses were significantly longer and more variable in speakers with ALS than in the control speakers. These results suggest that the algorithm provided an efficient and valid method for extracting pause and speech timing information from the optimally structured speech sample.

]]> Jordan R. Green et al. Respiratory Changes during Reading in Mandarin-Speaking Adolescents with Prelingual Hearing Impairment http://digitalcommons.unl.edu/specedfacpub/66 http://digitalcommons.unl.edu/specedfacpub/66 Wed, 01 Jun 2011 12:51:03 PDT Objective: Most people with severe to profound hearing impairment (SHI) exhibit speech breathing changes, but little is known about the breath group (BG) structure for this population. The purposes of this study were to investigate, compared to speakers with normal hearing, if Mandarin-speaking adolescents with prelingual SHI take inspirations more often at syntactically inappropriate positions and exhibit a difference in the temporal BG characteristics. Patients and Methods: Forty participants, 20 speakers with prelingual SHI and 20 normal-hearing controls matched for age, sex and education level were recruited. While wearing a circumferentially vented mask connected to a pneumotachograph, the subjects read three passages. The airflow signal was used to locate inspiratory loci in the speech samples. Temporal parameters of BG structure were derived from the acoustic signal. Results: The SHI group, compared to the control group, had significantly (1) more inspiratory loci at inappropriate and minor syntactic boundaries; (2) fewer syllables per BG, slower speaking rate, longer inter-BG pauses, and longer noninspiratory pauses, but comparable inspiratory duration, expiration duration, and BG duration. Conclusion: The slower speaking rate within BGs and longer inter-BG pauses mainly account for the respiratory changes in Mandarin-speaking adolescents with prelingual SHI.

]]> Wei-Chun Che et al. Breath Group Analysis for Reading and Spontaneous Speech in Healthy Adults http://digitalcommons.unl.edu/specedfacpub/65 http://digitalcommons.unl.edu/specedfacpub/65 Wed, 01 Jun 2011 12:00:38 PDT Aims: The breath group can serve as a functional unit to define temporal and fundamental frequency (f0) features in continuous speech. These features of the breath group are determined by the physiologic, linguistic, and cognitive demands of communication. Reading and spontaneous speech are two speaking tasks that vary in these demands and are commonly used to evaluate speech performance for research and clinical applications. The purpose of this study is to examine differences between reading and spontaneous speech in the temporal and f0 aspects of their breath groups.

Methods: Sixteen participants read two passages and answered six questions while wearing a circumferentially vented mask connected to a pneumotach. The aerodynamic signal was used to identify inspiratory locations. The audio signal was used to analyze task differences in breath group structure, including temporal and f0 components.

Results: The main findings were that spontaneous speech task exhibited significantly more grammatically inappropriate breath group locations and longer breath group duration than did the passage reading task.

Conclusion: The task differences in the percentage of grammatically inadequate breath group locations and in breath group duration for healthy adult speakers partly explain the differences in cognitive-linguistic load between the passage reading and spontaneous speech.

]]> Yu-Tsai Wang et al. Vowel Recognition from Continuous Articulatory Movements for Speaker-Dependent Applications http://digitalcommons.unl.edu/specedfacpub/64 http://digitalcommons.unl.edu/specedfacpub/64 Wed, 01 Jun 2011 11:29:49 PDT A novel approach was developed to recognize vowels from continuous tongue and lip movements. Vowels were classified based on movement patterns (rather than on derived articulatory features, e.g., lip opening) using a machine learning approach. Recognition accuracy on a single-speaker dataset was 94.02% with a very short latency. Recognition accuracy was better for high vowels than for low vowels. This finding parallels previous empirical findings on tongue movements during vowels. The recognition algorithm was then used to drive an articulation-to-acoustics synthesizer. The synthesizer recognizes vowels from continuous input stream of tongue and lip movements and plays the corresponding sound samples in near real-time.

]]> Jun Wang et al.