bluuebunny/crossref_metadata_2025 huggingface dataset:
Stuttering, Stressed Syllables, and Word Onsets
Authors: Hubbard Carol P.
Published: July 2014

The relationship of syllabic stress, word onsets, and stuttering was examined on selected words within a set of 40 carefully controlled sentences containing bisyllabic words with contrastive stress. Ten stuttering adults displayed significantly more stuttering on the word-initial syllables than on the subsequent (word-final) syllables, whereas stressed syllables were not stuttered significantly more than unstressed syllables. Participants displayed a greater tendency to stutter on word-onsets than stressed syllables within words. These findings are discussed with respect to potential relationships of stutter events to layers of metrical structure associated with speech production.
Comments Regarding the Investigation of Developmental Apraxia of Speech
Authors: Waldron Claire M.
Published: July 2014

The conclusions and discussion were based on only 16 children who were identified based on clearly described criteria. Those subjects have widely varying ages, unspecified treatment histories, and varying receptive language status. The authors did not claim that these results are generalizable to a larger population of children, but I fear that their results will be interpreted that way by others. Identifying unusual phrasal stress deficits in 8 of 16 children with suspected DAS should not be construed or implied as evidence for a diagnostic marker for a subtype of DAS.

I strongly agree with the authors that longitudinal studies of children with persistent and unusual speech disorders are needed. Studies concerning children's responses to treatment are also needed. Although models of adult onset apraxia (AOS) may provide useful procedures for measuring or describing speech and nonspeech characteristics of DAS, using AOS as a theoretical model or clinical analogy to DAS leads us to ask less relevant questions about children with unusual and persistent speech disorders. Children with suspected DAS are different from adults who have AOS. Children who have never spoken normally or used language normally are different from adults who have acquired a speech disorder after decades of using spoken and written language normally. In order to intervene efficiently and appropriately, we need to know whether and how children with DAS differ from other children, not how they might resemble adults with an acquired disorder.
Aging and High-Frequency Hearing Sensitivity
Authors: Wiley Terry L. , Cruickshanks Karen J. , Nondahl David M. , Tweed Ted S. , Klein Ronald , Klein Barbara E. K.
Published: July 2014

As part of a large population-based study of hearing and aging, ultra highfrequency (9–20 kHz) threshold measures are reported for 3396 participants grouped by age (48–59 years,
n
=1233; 60–69 years,
n
=1031; 70–79 years,
n
=851; 80–92 years,
n
=281). Ultra high-frequency (UHF) thresholds were higher for older age groups. The percentage of unmeasurable responses also was significantly higher for older age groups and for higher frequencies in the UHF range. The observed age effects remained significant after adjusting for gender. In general, UHF thresholds were significantly higher for men compared to those for women at lower UHF frequencies (9–14 kHz), but were not significantly different by gender for the highest UHF frequencies (16, 18, and 20 kHz). After accounting for hearing loss at traditional audiometric frequencies (250–8000 Hz), the age effect still remained; even for comparable degrees of sensorineural hearing loss, participants in older age groups evidenced higher UHF thresholds.
Optimizing the Reliability of Speech Recognition Scores
Authors: Gelfand Stanley A.
Published: July 2014

Speech recognition assessment involves a dilemma because clinicians want a test that is short and reliable, but statistical principles dictate that a short test is unreliable. Curves representing the variability of test scores based on the binomial model reveal that approximately 450 scorable items are needed in order to optimize the reliability of a speech recognition test. A testing approach was developed to achieve this sample size while retaining the principal features of the most commonly accepted speech recognition tests (i.e., monosyllabic words presented in an open-set format, verbal responses, and right/wrong scoring). It involves the use of an interactive computer program to present CNC words in 50 three-word groups, which are scored phonemically, resulting in 450 scorable items. Normal performance is described as a function of both presentation level and signal-to-noise ratio. Comparisons of test and retest scores for 100 individuals with normal hearing and 100 persons with sensorineural losses revealed that the approach achieves the degree of reliability predicted by the binomial model for both groups. Phoneme scores accounted for 99% of the variance of word scores for most of the performance range encountered in clinical practice, making it possible for test outcomes based on phonemic scoring to be expressed in terms of equivalent word recognition scores.
Prosodic Markers of Syntactic Boundaries in the Speech of 4-Year-Old Children With Normal and Disordered Language Development
Authors: Snow David
Published: July 2014

This study focuses on the potential role of prosodic "boundary features" in developmental disorders of morphosyntax. As exemplified melodically by the final portion of the falling tone and rhythmically by final syllable lengthening, boundary features mark the right edge of major constituent units in speech and thus phonetically reflect syntactic structure on the level of clauses and sentences. To resolve conflicting findings about the development of boundary features in children with specific language impairment (SLI), this study describes the falling tone and final syllable lengthening in the spontaneous speech of 10 four-year-old children with the phonologic-syntactic type of SLI and 10 four-year-old children with normal language development. The results—indicating that some prosodic boundary features are normal in preschoolers with SLI—show that impairments of morphology and syntax on the segmental level of the grammar do not implicate systematic deficits in syntax-sensitive features on the suprasegmental level. The potential dissociation between prosodic and morphosyntactic development is shown most clearly by the remarkable robustness of the falling tone, which was observed in 9 of the 10 children with SLI, in spite of the moderate to severe deficits they demonstrated in segmental phonology, morphosyntax, and mean length of utterance.
A Prominence Account of Syllable Reduction in Early Speech Development
Authors: Snow David
Published: July 2014

When young children produce multiword utterances and words that are polysyllabic in adult speech, they are most likely to omit unstressed syllables. Because unstressed syllables are omitted more often in weak-strong (iambic) than in strong-weak (trochaic) environments, a trochaic metrical theory has been proposed to account for the asymmetrical omission pattern. This paper presents an alternative explanation based on the notion of relative prosodic prominence. I propose that syllable prominence is a product of two orthogonal suprasegmental systems: one that marks stress/accent peaks and one that marks phrase boundaries. A two-component scale of prominence values reflecting the contributions of both systems was used to analyze single- and multi-word speech samples of 11 children 19 to 26 months of age. The results show that the prominence scale parsimoniously accounts not only for the bias toward syllable omissions in nontrochaic environments but also explains other types of syllable reduction not captured by metrical theories. Implications of the dual-system prosodic model are discussed in terms of possible contributions to a perceptually based theory of early polysyllabic and multiword patterns in child speech.
Maternal Responsivity Predicts the Prelinguistic Communication Intervention That Facilitates Generalized Intentional Communication
Authors: Yoder Paul J. , Warren Steven F.
Published: July 2014

Family systems theory posits that the relative effectiveness of early interventions will vary depending on various aspects of the family. This study tested whether maternal responsivity would predict the extent to which Prelinguistic Milieu Teaching (PMT) facilitated generalized intentional communication better than a contrast treatment that was conducted in a small group by a responsive adult (i.e., Responsive Small Group, RSG). Fifty-eight children with developmental disabilities in the prelinguistic communication period of development were randomly assigned to one of the two staff-implemented treatment groups. Thirty were assigned to RSG; 28 were assigned to PMT. Mothers were kept naive to the intervention methods, hypotheses, and measures. In families with mothers who responded to a high percentage of the children's communication acts at the pre-treatment period, the children in the PMT group used more frequent intentional communication in post-treatment generalization sessions with a trainer and mothers than did children in the RSG group. In the families with mothers who responded to fewer than 39% of their children's communication acts, children in the RSG intervention used more frequent intentional communication in post-treatment generalization sessions with the mothers than did children in the PMT intervention. Other family variables and no child variables that we measured could account for these findings.
Two- to Six-Year Controlled-Trial Stuttering Outcomes for Children and Adolescents
Authors: Hancock Karen , Craig Ashley , McCready Chris , McCaul Annette , Costello Deborah , Campbell Karen , Gilmore Gillian
Published: July 2014

This research is a long-term follow-up of a previously published, controlled trial on the effectiveness of 3 stuttering treatments (intensive smooth speech, parenthome smooth speech, and intensive electromyography feedback) for children and adolescents, aged 11 to 18 years, who stutter. The previous controlled trial showed all 3 treatments to be effective compared to nontreatment after 12 months. This paper reports on the treatment effectiveness after an average of 4 years post-treatment. Results demonstrate that treatment gains were maintained in the long term, with rates of stuttering similar to the 1-year postoutcomes. There were no significant differences among the 3 treatments in long-term effectiveness. This controlled study substantiates the claim that the treatments investigated will more than likely have substantial long-term benefits for the fluency and personality of children and adolescents who stutter.
Teaching Partner-Focused Questions to Individuals Who Use Augmentative and Alternative Communication to Enhance Their Communicative Competence
Authors: Light Janice C. , Binger Cathy , Agate Tracy L. , Ramsay Karen N.
Published: July 2014

A single-subject, multiple-probe experimental design was used to investigate the effect of instruction on the acquisition, generalization, and long-term maintenance of partner-focused questions (i.e., questions about communication partners and their experiences) by individuals who use augmentative and alternative communication (AAC). Six participants who had severe speech impairments and used AAC participated in the study; they ranged in age from 10 to 44 years, had a variety of disabilities, and used a range of AAC systems. Instruction used a least-to-most prompting hierarchy in real-world interactions and during simulations. All of the participants successfully learned to ask partner-focused questions spontaneously in social interactions; they required an average of approximately 6 hours of instruction (range: 3–11 hours). The participants generalized the use of partnerfocused questions to new situations in the natural environment and maintained use of partner-focused questions at least 2 months postinstruction; one participant required some "booster" instructional sessions 4 weeks postinstruction to maintain her long-term use of partner-focused questions. The participants all reported high levels of satisfaction with the outcomes of the instructional program, as did their facilitators. Members of the general public, blind to the goals of the study, judged the majority of the participants to be more competent communicators after instruction.
Tutorial
Authors: Gruber Frederic A.
Published: July 2014

Current demands for increased research attention to therapeutic efficacy, efficiency, and also for improved developmental models call for analysis of longitudinal outcome data. Statistical treatment of longitudinal speech and language data is difficult, but there is a family of statistical techniques in common use in medicine, actuarial science, manufacturing, and sociology that has not been used in speech or language research. Survival analysis is introduced as a method that avoids many of the statistical problems of other techniques because it treats time as the outcome. In survival analysis, probabilities are calculated not just for groups but also for individuals in a group. This is a major advantage for clinical work. This paper provides a basic introduction to nonparametric and semiparametric survival analysis using speech outcomes as examples. A brief discussion of potential conflicts between actuarial analysis and clinical intuition is also provided.
Time-Intensity Trading in the Late Auditory Evoked Potential
Authors: Eddins Ann Clock , Peterson Joelle Redner
Published: July 2014

The present study investigated physiological correlates of the time-intensity trading relationship in late components (N1, P2) of the auditory evoked potential. Late-potential and behavioral thresholds were estimated in five normal-hearing, young adult participants for 1000- and 4000-Hz tone bursts having durations of 8, 16, 32, 64, and 128 ms. The results showed that late-potential thresholds decreased by an average of 24 dB for 1000-Hz conditions and 18 dB for 4000-Hz conditions. Behavioral thresholds also improved by about 22 dB and 18 dB for 1000-Hz and 4000-Hz conditions, respectively. The slope of improvement for both late-potential and behavioral thresholds was on the order of –4 to –6 dB per doubling of stimulus duration, depending on stimulus frequency. Stimulus duration also influenced latency and amplitude measures of the N1 and P2 components such that response latency decreased and amplitude increased as stimulus duration increased. The present results demonstrate a time-intensity trading relationship in components of the late potentials that is consistent with previous psychophysical and physiological data.
Acoustic Characteristics of /s/ in Adolescents
Authors: Flipsen Peter , Shriberg Lawrence , Weismer Gary , Karlsson Heather , McSweeny Jane
Published: July 2014

The goal of the current study was to construct a reference database against which misarticulations of /s/ can be compared. Acoustic data for 26 typically speaking 9- to 15-year-olds were examined to resolve measurement issues in acoustic analyses, including alternative sampling points within the /s/ frication; the informativeness of linear versus Bark transformations of each of the 4 spectral moments of /s/ (Forrest, Weismer, Milenkovic, & Dougall, 1988); and measurement effects associated with linguistic context, age, and sex. Analysis of the reference data set indicates that acoustic characterization of /s/ is appropriately and optimally (a) obtained from the midpoint of /s/, (b) represented in linear scale, (c) reflected in summary statistics for the 1st and 3rd spectral moments, (d) referenced to individual linguistic-phonetic contexts, (e) collapsed across the age range studied, and (f) described individually by sex.
Development of Adult-Like Performance in Backward, Simultaneous, and Forward Masking
Authors: Buss Emily , Hall Joseph W. , Grose John H. , Dev Madhu B.
Published: July 2014

Some researchers have argued that specific language impairment (SLI) is associated with deficits in processing certain temporal aspects of auditory stimuli. One recent study (Wright et al ., 1997) suggests that backward masking in particular poses a problem for children with SLI, as compared to simultaneous or forward masking. Interpretation of this finding is complicated by the fact that very little is known about the development of normal, adult-like performance in these masking paradigms. The study reported here examined performance for children 5–11 years old on forward, simultaneous, and backward masking and compared their performance to that of adults. The data show a trend for improvement in performance with age in all three masking paradigms. There was no evidence for later or more gradual improvement in performance on the backward-masking paradigm. However, backward-masking thresholds were more variable than those in the other conditions and were subject to greater individual differences, even in the adult data set. Manipulation of masker bandwidth yielded no evidence for more adult-like performance in the child data with the wider bandwidth masker. Additional data collected on two naive adult observers show a marked improvement in backward-masking performance over time, suggesting that detection with these stimuli might be particularly subject to practice effects.
The Integration of Laughter and Speech in Vocal Communication
Authors: Nwokah Eva E. , Hsu Hui-Chin , Davies Patricia , Fogel Alan
Published: July 2014

Laughter in infant-directed speech was examined in 13 mother-infant pairs to investigate the possible co-occurrence of speech and laughter. Contrary to previous findings in adult-adult social interaction, all mothers produced speech simultaneously with laughter in up to 50% of laughs. In most of these speech-laughs the onset of laugh and speech was simultaneous. Laughter occurred on both function and content words and was more likely to occur on approximately 2 words and on utterances that were statements rather than questions or exclamations. Laughter and speech are different outcomes produced from a reorganization of the same vocal/anatomical parameters. A 3rd outcome is possible in the form of speech-laughs utilizing features from both laughter and speech. In speech-laughs, the duration of the vocalization was more likely to increase, and the changes in the utterance were likely to include 1 or more of the features of vowel elongation, syllabic pulsation, breathiness, and pitch change. These findings and individual variations in the resulting vocal output are discussed from a dynamic systems perspective. It is argued that neither speech nor laughter is dominant when both are combined, but that this is a more complex vocal outcome produced with idiosyncratic flexibility within stable temporal and physiological constraints.
Speech Perception and Verbal Memory in Children With and Without Histories of Otitis Media
Authors: Mody Maria , Schwartz Richard G. , Gravel Judith S. , Ruben Robert J.
Published: July 2014

Two groups of children, with (n=7) and without (n=7) first-year histories of otitis media, were participants in a longitudinal study that included periodic audiological and medical evaluations during the first year of life. At age 9, these children were tested on a series of speech perception and verbal short-term memory tasks using stimuli of varying degrees of phonetic contrast. Although the otitis-positive group performed less accurately than the otitis-free group, the pattern of errors was the same for the two groups. The performances of the children with and without positive histories of otitis media were negatively affected by an increase in phonetic similarity of the stimulus items. The two groups, however, did not differ on identification or on temporal-order recall when the speech sounds were differentiated by multiple features. These findings provide evidence of subtle, long-term effects of early episodes of otitis media on phonological representations and on working memory.
An Examination of Verbal Working Memory Capacity in Children With Specific Language Impairment
Authors: Weismer Susan Ellis , Evans Julia , Hesketh Linda J.
Published: July 2014

This study investigated verbal working memory capacity in children with specific language impairment (SLI). The task employed in this study was the Competing Language Processing Task (CLPT) developed by Gaulin and Campbell (1994). A total of 40 school-age children participated in this investigation, including 20 with SLI and 20 normal language (NL) age-matched controls. Results indicated that the SLI and NL groups performed similarly in terms of true/false comprehension items, but that the children with SLI evidenced significantly poorer word recall than the NL controls, even when differences in nonverbal cognitive scores were statistically controlled. Distinct patterns of word-recall errors were observed for the SLI and NL groups, as well as different patterns of associations between CLPT word recall and performance on nonverbal cognitive and language measures. The findings are interpreted within the framework of a limited-capacity model of language processing.
Maternal Education and Measures of Early Speech and Language
Authors: Dollaghan Christine A. , Campbell Thomas F. , Paradise Jack L. , Feldman Heidi M. , Janosky Janine E. , Pitcairn Dayna N. , Kurs-Lasky Marcia
Published: July 2014

The present study was designed to determine whether 4 measures of children’s spontaneous speech and language differed according to the educational level of the children’s mothers. Spontaneous language samples from 240 three-year-old children were analyzed to determine mean length of utterance in morphemes (MLUm), number of different words (NDW), total number of words (TNW), and percentage of consonants correct (PCC). A norm-referenced, knowledge-dependent measure of language comprehension, the Peabody Picture Vocabulary Test–Revised (PPVT–R), was also included for purposes of comparison with the spontaneous measures. Three levels of maternal education were compared: less than high school graduate, high school graduate, and college graduate. Trend analyses showed statistically significant linear trends across educational levels for MLUm, NDW, TNW, and PPVT–R; the trend for PCC was not significant. The relationship of maternal education and other sociodemographic variables to measures of children’s language should be examined before using such measures to identify children with language disorders.

KEY WORDS: child language disorders, child language development, child language assessment, test bias, maternal education
Metrical Analysis of the Speech of Children With Suspected Developmental Apraxia of Speech
Authors: Velleman Shelley L. , Shriberg Lawrence D.
Published: July 2014

Previous studies have shown that metrical analysis accounts for syllable omissions in young normally developing children better than prior perspectives. This approach has not yet been applied to children with disorders. Inappropriate sentential stress has been proposed as a diagnostic marker for a subgroup of children with suspected developmental apraxia of speech (SD-DAS), suggesting that the application of metrical perspectives to this population may be appropriate. This report extends the goal of identifying diagnostic markers for SD-DAS using analytic procedures from metrical phonology. The lexical metrical patterns of children with SD-DAS were compared to those of a group of children with speech delay (SD) to verify the applicability of metrical constructs to children with disorders while at the same time seeking lexical stress characteristics that might be useful for differential diagnosis. The lexical stress errors of children in both the SD and SD-DAS disorder groups were found to conform to patterns identified in metrical studies of younger normally developing children, confirming the applicability of this approach to children with disorders. Lexical metrical patterns did not differentiate the groups from each other. However, syllable omissions persisted to much later ages in the SD-DAS subjects, especially those children previously identified as having inappropriate phrasal stress. Further metrical studies of the speech of children with suspected SD-DAS are needed, both at the lexical and the sentential level, using both perceptual and acoustic measures.
Prosodic Influences on Speech Production in Children With Specific Language Impairment and Speech Deficits
Authors: Goffman Lisa
Published: July 2014

It is often hypothesized that young children's difficulties with producing weak-strong (iambic) prosodic forms arise from perceptual or linguistically based production factors. A third possible contributor to errors in the iambic form may be biological constraints, or biases, of the motor system. In the present study, 7 children with specific language impairment (SLI) and speech deficits were matched to same age peers. Multiple levels of analysis, including kinematic (modulation and stability of movement), acoustic, and transcription, were applied to children's productions of iambic (weak-strong) and trochaic (strong-weak) prosodic forms. Findings suggest that a motor bias toward producing unmodulated rhythmic articulatory movements, similar to that observed in canonical babbling, contribute to children's acquisition of metrical forms. Children with SLI and speech deficits show less mature segmental and speech motor systems, as well as decreased modulation of movement in later developing iambic forms. Further, components of prosodic and segmental acquisition develop independently and at different rates.
Patterns of Orofacial Movement Velocity Across Variations in Speech Rate
Authors: McClean Michael D.
Published: July 2014

To understand the clinical aspects of speech rate control, a clearer picture is needed of how orofacial structures are coordinated across variations in speech rate. To address this problem, patterns of orofacial tangential velocity or speed were analyzed in a group of 9 normal speakers as they produced the utterance “a bad daba” at fast, normal, and slow speech rates. An electromagnetic system was used to record the movements of the upper lip, lower lip, jaw, and tongue. Measures of the magnitude of peak tangential velocities were obtained across the four structures. Orofacial velocities consistently decreased at slow rates relative to normal rates, whereas at fast rates increased and decreased velocities were observed in an equivalent number of cases. Significant correlations frequently were obtained across speech rate between lip, tongue, and jaw velocities. Upper and lower lip velocities showed consistent positive correlations with one another, whereas marked intersubject differences were observed in the sign of jaw-related correlations. Repeated testing on 3 subjects indicated a high degree of consistency within subjects in the overall patterns of mean velocity for the different structures. Results are discussed in relation to possible motor control differences underlying fast and slow speech, neural coupling of muscle systems, and jaw-related individual differences in speech motor coordination.
Development of Isolation-Induced Vocal Behavior in Normal-Hearing and Deafened Guinea Pig Infants
Authors: Arch-Tirado E. , McCowan B. , Saltijeral-Oaxaca J. , Coronado I. Zarco de , Licona-Bonilla J.
Published: July 2014

Infants in many different animal species require auditory information from conspecifics to learn appropriate responses to important environmental and social cues. Isolation calls are emitted by infant guinea pigs in contexts of social separation from their mothers. The aim of the present study was to examine the ontogeny of the isolation calls in normal-hearing and deafened infant guinea pigs, from 2 to 40 days postpartum and to determine the role of hearing maternal vocalization in infant guinea pig vocal responses in contexts of social proximity and isolation. Female newborn pigmented guinea pigs (
Cavia porcellus
) were housed with their birth mother and siblings. Water and dry food were available
ad libitum
. One day postpartum, the cochlea of infants in the experimental group was destroyed. The control group consisted of normal-hearing female siblings. Vocalizations from infants in the experimental and control groups were recorded for 6 minutes when with the mother before isolation, 6 minutes when alone, and then 6 minutes when with the mother after reunion. Recordings were made 5 days per week from 2 to 40 days after birth. The duration of calling was calculated for each 6-minute period of recording. Results demonstrated that deaf infants vocalize more than normal-hearing infants during social isolation from their mothers. Vocal activity of isolated deaf and normal-hearing infants decreased substantially over development, almost disappearing by the end of the study period. These results indicate that maternal vocal behavior modulates the vocal responses of guinea pigs early in infant development and supports other evidence that the guinea pig offers a viable model for investigating audition in deaf and normal-hearing human infants.
Respiratory Control in Stuttering Speakers
Authors: Denny Margaret , Smith Anne
Published: July 2014

This study tested the hypothesis that, in stuttering speakers, relations between the neural control systems for speech and life support, or metabolic breathing, may differ from relations previously observed in normally fluent subjects. Bilaterally coherent high-frequency oscillations in inspiratory-related EMGs, measured as maximum coherence in the frequency band of 60–110 Hz (MC-HFO), were used as indicators of participation by the brainstem controller for metabolic breathing in 10 normally fluent and 10 stuttering speakers. In all controls and most stuttering subjects, MC-HFO for speech was higher than or comparable to MC-HFO for deep breathing. For 4 stuttering subjects, higher MC-HFO was observed for speech than for deep breathing. Comparison of deep breathing to a speechlike breathing task yielded similar results. No relationship between MC-HFO during speech and severity of disfluency was observed. We conclude that in some stuttering speakers, the relations between respiratory controllers are atypical, but that high participation by the HFO-producing circuitry in the brainstem during speech is not sufficient to disrupt fluency.
Improving the Positive Predictive Value of Screening for Developmental Language Disorder
Authors: Klee Thomas , Pearce Kim , Carson David K.
Published: July 2014

In a previous study, we reported the results of an early language screening program in which 306 children were screened using a parent-report questionnaire sent through the mail (Klee et al., 1998). A sample of the children screened were given clinical evaluations within a month of screening (n=64) and again 1 year later (n=36). Although the screening program correctly identified 91% of 2-year-olds with language delay, it produced a large number of over-referrals. In the present study we examine a revised screening criterion designed to reduce the number of false positives. The revised criterion generated fewer positive screens overall than the original and resulted in improved specificity (96% vs. 87%) and positive predictive value (77% vs. 51%), while maintaining the high sensitivity (91%) and negative predictive value (98%) of the original criterion. We also propose a screening score based on the new criterion, designed to inform the process of deciding which children to bring in for further evaluation.
Tinnitus and Cognitive Interference
Authors: Andersson Gerhard , Eriksson Jan , Lundh Lars-Gunnar , Lyttkens Leif
Published: July 2014

The aim of this study was to investigate cognitive interference caused by tinnitus by means of a modified version of the Stroop color-word test. In a mixed-design study, the performances of tinnitus patients (
n
=23) and healthy controls with normal hearing (
n
=23) were compared on three versions of the Stroop test: the original version, a modified version including physical-threat words, and a tinnitus version for which tinnitus words (descriptors of tinnitus; e.g.,
peep
) were derived empirically. Matched control conditions (words) were included for all three versions, yielding a total of six screens that were presented on a computer. Participants in the control group were matched with the patients for age and gender. Main dependent measures were performance on the Stroop tests in terms of total time for completing each test. Also included were the Tinnitus Questionnaire (TQ), the Beck Depression Inventory (BDI), the state version of the Spielberger Trait State Anxiety Inventory (STAI-S), and a subtest from the Wechsler Adult Intelligence Scale measuring verbal ability. Results showed that tinnitus patients performed significantly slower on all six test conditions. The classical Stroop color-word interference was replicated in both groups. Also, an effect for physical-threat words was found for both groups. Our expected tinnitus word interference could not be established. Patients scored significantly higher than controls on the BDI and the STAI, but these measures did not correlate with the Stroop results. In conclusion, the results indicate that tinnitus patients have impaired cognitive performance overall, as measured by these variations of the Stroop paradigm, but hearing impairment cannot be excluded as a possible confounder.
Effect of a Single-Channel Wide Dynamic Range Compression Circuit on Perception of Stop Consonant Place of Articulation
Authors: Hedrick Mark S. , Rice Tracie
Published: July 2014

Previous studies have shown that altering the amplitude of a consonant in a specific frequency region relative to an adjacent vowel's amplitude in the same frequency region will affect listeners' perception of the consonant place of articulation. Hearing aids with single-channel, fast-acting wide dynamic range compression (WDRC) alter the overall consonant-vowel (CV) intensity ratio by increasing consonant energy. Perhaps one reason WDRC has had limited success in improving speech recognition performance is that the natural amplitude balances between consonant and vowel are altered in crucial frequency regions, thus disturbing the aforementioned amplitude cue for determining place of articulation. The current study investigated the effect of a WDRC circuit on listeners' perception of place of articulation when the relative amplitude of consonant and vowel was manipulated. The stimuli were a continuum of synthetic CV syllables stripped of all place cues except relative consonant amplitudes. Acoustic analysis of the CVs before and after hearing aid processing showed a predictable increase in high-frequency energy, particularly for the burst of the consonant. Alveolar bursts had more high-frequency energy than labial bursts. Twenty-five listeners with normal hearing and 5 listeners with sensorineural hearing loss labeled the consonant sound of the CV syllables in unaided form and after the syllables were recorded through a hearing aid with single-channel WDRC. There were significantly more listeners who were unable to produce a category boundary when labeling the aided stimuli. Of those listeners who did yield a category boundary for both aided and unaided stimuli, there were significantly more alveolar responses for the aided condition. These results can be explained by the acoustic analyses of the aided stimuli.
Laryngeal Factors in Voiceless Consonant Production in Men, Women, and 5-Year-Olds
Authors: Koenig Laura L.
Published: July 2014

Voicing control in stop consonants has often been measured by means of voice onset time (VOT) and discussed in terms of interarticulator timing. However, control of voicing also involves details of laryngeal setting and management of sub- and supraglottal pressure levels, and many of these factors are known to undergo developmental change. Mechanical and aerodynamic conditions at the glottis may therefore vary considerably in normal populations as functions of age and/or sex. The current study collected oral airflow, intraoral pressure, and acoustic signals from normal English-speaking adults and children producing stop consonants and /h/ embedded in a short carrier utterance. Measures were made of stop VOTs, /h/ voicing and flow characteristics, and subglottal pressure during /p/ closures. Clear age and gender effects were observed for /h/: Fully voiced /h/ was most common in men, and /h/ voicing and flow data showed the highest variability among the 5-year-olds. For individual participants, distributional measures of VOT in /p t/ were correlated with distributional measures of voicing in /h/. The data indicate that one cannot assume comparable laryngeal conditions across speaker groups. This, in turn, implies that VOT acquisition in children cannot be interpreted purely in terms of developing interarticulator timing control, but must also reflect growing mastery over voicing itself. Further, differences in laryngeal structure and aerodynamic quantities may require men and women to adopt somewhat different strategies for achieving distinctive consonantal voicing contrasts.
An Acoustic Study of Coarticulation in Dysarthric Speakers With Parkinson Disease
Authors: Tjaden Kris
Published: July 2014

Anticipatory vowel coarticulation in obstruent + vowel syllables was studied for 9 dysarthric males with mild to moderate idiopathic Parkinson disease (PD) and a group of 10 healthy males. In addition to studying coarticulatory differences for speakers' habitual rate repetitions, a graded speaking rate task was used to investigate the effect of rate variation on coarticulation. The ratio of F2 onset frequency/F2 target frequency was used to infer coarticulation (i.e., ratios of 1.0 indicate complete vowel harmony at vowel onset, and ratios greater than 1.0 indicate relatively less coarticulation). Because F2 onset frequency is a relatively novel measure of coarticulation, a more common measure of anticipatory vowel coarticulation—fricative F2—was obtained for a subset of the speech stimuli and compared to F2 onset measures. Ratios of fricative F2/F2 target frequency also were computed to infer coarticulation and the results were compared to the F2 onset/F2 target ratios. The results indicated a modest relationship between F2 onset frequency and fricative F2 for both speaking tasks and speaker groups, with a stronger relationship for the graded rate task. Regression analyses for the graded rate task further indicated that longer vowel durations were associated with larger ratios for both speaker groups. Thus, coarticulation tended to increase with faster rates and decrease with slower rates, although the relationship was more systematic for control speakers. Ratios for the habitual task tended to be smaller for speakers with PD, suggesting increased coarticulation relative to control speakers. This effect was not entirely attributable to the more rapid speaking rates for speakers with PD. Because habitual rate F2 onset/F2 target ratios tended to underestimate the extent to which coarticulation was increased for speakers with PD—compared to the fricative F2/F2 target ratios—measures other than F2 onset should be used to infer
absolute
differences in extent of coarticulation for speakers with PD and healthy controls.
SIG 1 Perspectives Vol. 19, No. 4, October 2012
Authors: Petersen Douglas B. , Spencer Trina D.
Published: July 2014

Sorry, this activity is no longer available for CEUs. Visit the SIG 1 page on the
ASHA Store
to see available CE activities.

Use the CE questions PDF here as study questions to guide your Perspectives reading.
Right Hemisphere Brain Damage in Children
Authors: Trauner Doris A.
Published: July 2014

Adults with right hemisphere (RH) damage have a characteristic cognitive profile of impaired facial recognition and visual spatial skills, contralateral neglect, and aprosodia, with relatively intact propositional language. The adverse effects of childhood RH damage are more subtle and do not follow the adult pattern following RH injury.

This article reviews evidence that the RH is specialized early in life for certain cognitive functions, including comprehension of affective prosody and visual spatial analysis. Other cognitive functions such as facial recognition, language, and expressive prosody appear to have more bilateral representation during early development. There is also strong evidence for plasticity in the developing RH that allows reorganization to take place following focal injury. Such differences in neural networks during development may account for the good functional recovery in children with perinatal RH brain damage.
SIG 13 Perspectives Vol. 21, No. 4, December 2012
Authors: Kazandjian Marta , Dikeman Karen
Published: July 2014

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Use the CE questions PDF here as study questions to guide your Perspectives reading.
SIG 5 Perspectives Vol. 22, No. 2, October 2012
Authors: Jones David L.
Published: July 2014

Sorry, this activity is no longer available for CEUs. Visit the SIG 5 page on the
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to see available CE activities.

Use the CE questions PDF here as study questions to guide your Perspectives reading.
Universal tight binding model for chemical reactions in solution and at surfaces. I. Organic molecules
Authors: Sheppard T. J. , Lozovoi A. Y. , Pashov D. L. , Kohanoff J. J. , Paxton A. T.
Published: July 2014

As is now well established, a first order expansion of the Hohenberg–Kohn total energy density functional about a trial input density, namely, the Harris–Foulkes functional, can be used to rationalize a non self consistent tight binding model. If the expansion is taken to second order then the energy and electron density matrix need to be calculated self consistently and from this functional one can derive a charge self consistent tight binding theory. In this paper we have used this to describe a polarizable ion tight binding model which has the benefit of treating charge transfer in point multipoles. This admits a ready description of ionic polarizability and crystal field splitting. It is necessary in constructing such a model to find a number of parameters that mimic their more exact counterparts in the density functional theory. We describe in detail how this is done using a combination of intuition, exact analytical fitting, and a genetic optimization algorithm. Having obtained model parameters we show that this constitutes a transferable scheme that can be applied rather universally to small and medium sized organic molecules. We have shown that the model gives a good account of static structural and dynamic vibrational properties of a library of molecules, and finally we demonstrate the model's capability by showing a real time simulation of an enolization reaction in aqueous solution. In two subsequent papers, we show that the model is a great deal more general in that it will describe solvents and solid substrates and that therefore we have created a self consistent quantum mechanical scheme that may be applied to simulations in heterogeneous catalysis.
Design of interferometer system for Keda Torus eXperiment using terahertz solid-state diode sources
Authors: Xie Jinlin , Wang Haibo , Ding Weixing , Li Hong , Lan Tao , Liu Adi , Liu Wandong , Yu Changxuan
Published: July 2014

A solid-state source based terahertz (THz) interferometer diagnostic system has been designed and characterized for the Keda Torus eXperiment (KTX). The THz interferometer utilizes the planar diodes based frequency multiplier (X48) to provide the probing beam at fixed frequency 0.650 THz, and local oscillator is provided by an independent solid-state diode source with tunable frequency (0.650 THz +/− 10 MHz). Both solid-state sources have approximately 1 mW power. The planar-diode mixers optimized for high sensitivity, ∼750 mV/mW, are used in the heterodyne detection system, which permits multichannel interferometer on KTX with a low phase noise. A sensitivity of ⟨nel⟩min = 4.5 × 1016 m−2 and a temporal resolution of 0.2 μs have been achieved during the initial bench test.
All-electron GW quasiparticle band structures of group 14 nitride compounds
Authors: Chu Iek-Heng , Kozhevnikov Anton , Schulthess Thomas C. , Cheng Hai-Ping
Published: July 2014

We have investigated the group 14 nitrides (M3N4) in the spinel phase (γ-M3N4 with M = C, Si, Ge, and Sn) and β phase (β-M3N4 with M = Si, Ge, and Sn) using density functional theory with the local density approximation and the GW approximation. The Kohn-Sham energies of these systems have been first calculated within the framework of full-potential linearized augmented plane waves (LAPW) and then corrected using single-shot G0W0 calculations, which we have implemented in the modified version of the Elk full-potential LAPW code. Direct band gaps at the Γ point have been found for spinel-type nitrides γ-M3N4 with M = Si, Ge, and Sn. The corresponding GW-corrected band gaps agree with experiment. We have also found that the GW calculations with and without the plasmon-pole approximation give very similar results, even when the system contains semi-core d electrons. These spinel-type nitrides are novel materials for potential optoelectronic applications because of their direct and tunable band gaps.
Diagnosing collisions of magnetized, high energy density plasma flows using a combination of collective Thomson scattering, Faraday rotation, and interferometry (invited)
Authors: Swadling G. F. , Lebedev S. V. , Hall G. N. , Patankar S. , Stewart N. H. , Smith R. A. , Harvey-Thompson A. J. , Burdiak G. C. , de Grouchy P. , Skidmore J. , Suttle L. , Suzuki-Vidal F. , Bland S. N. , Kwek K. H. , Pickworth L. , Bennett M. , Hare J. D. , Rozmus W. , Yuan J.
Published: July 2014

A suite of laser based diagnostics is used to study interactions of magnetised, supersonic, radiatively cooled plasma flows produced using the Magpie pulse power generator (1.4 MA, 240 ns rise time). Collective optical Thomson scattering measures the time-resolved local flow velocity and temperature across 7–14 spatial positions. The scattering spectrum is recorded from multiple directions, allowing more accurate reconstruction of the flow velocity vectors. The areal electron density is measured using 2D interferometry; optimisation and analysis are discussed. The Faraday rotation diagnostic, operating at 1053 nm, measures the magnetic field distribution in the plasma. Measurements obtained simultaneously by these diagnostics are used to constrain analysis, increasing the accuracy of interpretation.
Note: A simple broad bandwidth undersampling frequency-domain digital diffuse optical spectroscopy system
Authors: Jung Justin , Istfan Raeef , Roblyer Darren
Published: July 2014

Near-Infrared frequency-domain technologies, such as Diffuse Optical Spectroscopy (DOS), have demonstrated growing potential in a number of clinical applications. The broader dissemination of this technology is limited by the complexity and cost of instrumentation. We present here a simple system constructed with off-the-shelf components that utilizes undersampling for digital frequency-domain dDOS measurements. Broadband RF sweeps (50–300 MHz) were digitally sampled at 25 MSPS; amplitude, phase, and optical property extractions were within 5% of network analyzer derived values. The use of undersampling for broad bandwidth dDOS provides a significant reduction in complexity, power consumption, and cost compared with high-speed ADCs and analog techniques.