bluuebunny/crossref_metadata_2025 huggingface dataset:
The Conceptual Basis for Morpheme Learning Problems in Children With Specific Language Impairment
Authors: Connell Phil J. , Stone C. Addison
Published: July 2014

Two groups of children were exposed to instances of a nonlinguistic conceptual rule under controlled instructional conditions to determine whether the problems children with specific language impairment (SLI) have learning and accessing language rules extend beyond the language domain into the general cognitive domain. The performance of 20 children with SLI, aged 5:0 to 6:11 (years:months), was compared to that of 20 normally developing children matched for age and nonverbal ability. These children were taught under two instructional conditions that differed only in whether the child was asked to imitate the solution to a conceptual problem after each demonstration (imitation) or merely to observe it (modeling). Contrary to previous findings regarding linguistic rule-learning using auditory or visual symbol systems and similar instructional conditions, no difference was found between the extent of overall learning displayed by the normally developing children and those with SLI. Also, the performance of the children with SLI was not uniquely better under the imitation condition than under modeling, as had been the case with the learning of a novel morpheme in an auditory linguistic task. These results are interpreted as confirming the earlier assumption that the generally lower overall learning rate of the children with SLI on both the auditory and visual tasks reflects a specific linguistic rule-learning difficulty, rather than a general deficiency in rule induction.
Speech Sample Size and Test-Retest Stability of Connected Speech Measures for Adults With Aphasia
Authors: Brookshire Robert H. , Nicholas Linda E.
Published: July 2014

The effect of speech sample size on the test-retest stability of two measures of connected speech—words per minute (WPM) and percent of words that are correct information units (Percent CIUs)—was evaluated. A standard set of 10 stimuli was used to elicit connected speech from 20 non-brain-damaged adults and 20 adults with aphasia. Each subject’s responses to the 10 stimuli were transcribed and scored for WPM and Percent CIUs. Then each subject’s responses to the 10 stimuli were randomly divided to produce smaller speech samples representing his or her responses to 1, 2, 3, 4, 5, and 7 stimuli. The test-retest stability of the WPM and Percent ClUs measures was then evaluated for each of the smaller sample sizes and for the complete 10-stimulus sample. For both groups, the test-retest stability of the two measures increased as sample size increased, with the greatest increases occurring as samples increased in size from those representing 1 stimulus to those representing 4 or 5 stimuli, with smaller increases in stability thereafter. In general, these results suggest that the best balance between high test-retest stability and the time and effort required to transcribe and score speech samples can be achieved with samples representing 4 or 5 stimuli (an average of 300 to 400 words for aphasic subjects), although this will vary across individuals.
A Method for Studying the Generalized Slowing Hypothesis in Children With Specific Language Impairment
Authors: Kail Robert
Published: July 2014

The present work was conducted to demonstrate a method that could be used to assess the hypothesis that children with specific language impairment (SLI) often respond more slowly than unimpaired children on a range of tasks. The data consisted of 22 pairs of mean response times (RTs) obtained from previously published studies; each pair consisted of a mean RT for a group of children with SLI for an experimental condition and the corresponding mean RT for a group of children without SLI. If children with SLI always respond more slowly than unimpaired children and by an amount that does not vary across tasks, then RTs for children with SLI should increase linearly as a function of RTs for age-matched control children without SLI. This result was obtained and is consistent with the view that differences in processing speed between children with and without SLI reflect some general (i.e., non-task specific) component of cognitive processing. Future applications of the method are suggested.
Comparing Abilities of Children With Profound Hearing Impairments to Learn Consonants Using Electropalatography or Traditional Aural.Oral Techniques
Authors: Dagenais Paul A. , Critz-Crosby Paula , Fletcher Samuel G. , McCutcheon Martin J.
Published: July 2014

Two groups of nine children with profound hearing impairments and low intelligibility were taught to produce the consonants /t,d,k,g,s,z∫/ using either electropalatographic (palatometry) or traditional aural-oral techniques. Testing was completed pre-, immediately post-, and 6 months post-treatment by examining productions of CV syllables (V=/i,a/) using electropalatography-determined linguapalatal contacts and listener identifications. Intelligibility was also measured using the CID Picture Speech Intelligibility Evaluation (SPINE) test. Both groups improved their consonant productions as a result of 26 50-minute sessions. Sessions were given twice daily over 3- to 4-week training periods. Immediately post-treatment, the electropalatography-trained subjects produced better consonants as measured by linguapalatal contact patterns and listener identifications. The linguapalatal-contact patterns learned by the electropalatography-trained group better matched normal speaker productions than did those of the traditionally trained group. Both groups showed equal improvement for both post-treatment conditions when tested with the CID SPINE test. Although further research is needed, the results of this study suggest that electropalatographic techniques are, at least, equal alternatives to traditional aural-oral speech training techniques for speakers with profound hearing impairments.
Subjective Anxiety Measurements and Cortisol Responses in Adults Who Stutter
Authors: Blood Gordon W. , Blood Ingrid M. , Bennett Stephanie , Simpson Kathleen C. , Susman Elizabeth J.
Published: July 2014

Anxiety, as measured by self-report inventories and salivary cortisol levels, was examined in 11 males who stutter and 11 males who do not stutter during baseline, low stress, and high stress sessions. During the high stress session salivary cortisol was significantly greater in persons who stutter than in persons who do not stutter. No significant differences were found between the two groups on the State-Anxiety Inventory, Trait-Anxiety Inventory, or the Personal Report of Communication Apprehension. Significant differences in anxiety levels among the baseline, low stress, and high stress sessions for both groups of subjects were found for the State-Anxiety Inventory. No other significant differences or relationships were found between the two groups.
An Investigation of Vowel Organization in Speakers With Severe and Profound Hearing Loss
Authors: McCaffrey Helen A. , Sussman Harvey M.
Published: July 2014

Vowel auditory formant distances were obtained from speakers with hearing loss to investigate how perceptual constraints affect the contrastiveness and intelligibility of their spoken vowels. These distances were evaluated in relation to the 3-Bark critical distance principle for vowel height and place as described by Syrdal (1985) and Syrdal and Gopal (1986). Seven speakers with profound hearing loss, 10 with severe hearing loss, and seven with normal hearing produced the vowels /u/, /i/, /r/, /æ/, /a/, and /v/ in an /hVt/ context. Vowel formants and fundamental frequencies were obtained with acoustic spectrographic and LPC analysis and converted to Bark values to establish auditory formant distances. Confusion matrices were constructed from normal listeners’ identifications of recorded vowel productions. When frequency data were transformed to a Bark auditory scale, increasing convergence of vowel targets was obtained with increase in hearing loss. Percent correct identifications of the vowels produced by the three groups reflected speaker group differences seen in vowel contrastiveness/ overlap in auditory phonetic space. Four levels of performance based on error incidence and type were determined. F1-F0 by F3-F2 Bark distance coordinate plots of a given speaker’s vowel space reflected the differential intelligibility scores shown by confusion matrices of individual speakers from the four performance levels. Vowel organization by speakers with hearing loss was influenced by (a) formant critical distance, and (b) formant audibility. The least audible formants, F2 and F3, showed the greatest effects of severe and profound hearing loss. F1 and F0 showed further change with the most profound losses and revealed individual differences as well.
Analysis of Vocal Disorders With Methods From Nonlinear Dynamics
Authors: Herzel Hanspeter , Berry David , Titze Ingo R. , Saleh Marwa
Published: July 2014

Several authors have recently demonstrated the intimate relationship between nonlinear dynamics and observations in vocal fold vibration (Herzel, 1993; Mende, Herzel, & Wermke, 1990; Titze, Baken, & Herzel, 1993). The aim of this paper is to analyze vocal disorders from a nonlinear dynamics point of view. Basic concepts and analysis techniques from nonlinear dynamics are reviewed and related to voice. The voices of several patients with vocal disorders are analyzed using traditional voice analysis techniques and methods from nonlinear dynamics. The two methods are shown to complement each other in many ways. Likely physiological mechanisms of the observed nonlinear phenomena are presented, and it is shown how much of the terminology in the literature describing rough voice can be unified within the framework of nonlinear dynamics.
Judgments of Stuttered and Nonstuttered Intervals by Recognized Authorities in Stuttering Research
Authors: Cordes Anne K. , Ingham Roger J.
Published: July 2014

The study reported in this paper gathered judgments of stuttering on brief (5.0-sec) audiovisual speech samples taken from six adults who stuttered. Judgments were made by 10 highly experienced authorities on stuttering treatment and research, located in seven different universities or clinical research centers. Results showed considerable agreement between pairs of judges working in the same center, but large and potentially fundamental differences were identified in the amount of stuttering recorded in different centers. Approximately 40% of the 5.0-sec speech intervals used in this study were assigned the same judgment, either Stuttered or Nonstuttered, by all judges on two judgment occasions. The possibility that these intervals may serve as a core for establishing an across-center standard for behavioral judgments of stuttering is discussed.
Acoustic Correlates of Stress in Young Children's Speech
Authors: Kehoe Margaret , Stoel-Gammon Carol , Buder Eugene H.
Published: July 2014

This study examined the acoustic correlates of stress in children’s productions of familiar words. Previous research has employed experimental words rather than familiar words to examine children’s phonetic marking of stress, or has not adequately controlled for phonetic environment. Subjects in this study included 22 children, aged 18–30 months, and 6 adults. Fundamental frequency, duration, and amplitude measures were extracted from stressed and unstressed syllables in two types of comparisons: one that controlled phonetic environment and syllable position (interword) and one that measured the relative effects of stress within the same word (intraword). When the tokens were analyzed on the basis of target stress pattern, results revealed no differences between adults and children in their acoustic marking of stress. Listener judgments showed that approximately 30% of children’s two-syllable productions were coded unreliably or were perceived as inaccurately stressed. Overall findings indicate that children control fundamental frequency, amplitude, and duration to derive perceptually identifiable stress contrasts in the majority of their productions but they are not completely adult-like in their marking of stress.
Effects of Signal and Masker Uncertainty on Children’s Detection
Authors: Allen Prudence , Wightman Frederic
Published: July 2014

This paper reports the results of two experiments that examined the effects of signal and masker uncertainty on preschool-age children’s and adults’ detection of tonal signals in noise maskers. In Experiment 1 (signal uncertainty) the signal was randomly at 501 or 2818 Hz. The majority of the adult listeners showed a slight decrement in performance consistent with an ability to monitor both frequencies simultaneously. The majority of the children, however, showed no decrement in performance, suggesting that the children may not have focused attention at the signal frequency even when it was fixed. In Experiment 2 (masker uncertainty), random-frequency, random-level, tonal distracters were added to each interval of the 2 alternative-forced-choice (2afc) procedure. The effect of masker uncertainty was much larger than that of signal uncertainty. For most of the adult listeners and some of the children, the distracters produced higher thresholds (on average by 10 dB) and shallower psychometric function slopes. For most of the children, thresholds increased by 20 dB or more and psychometric functions were often nearly flat.

This paper reports the results of two experiments that examined the effects of signal and masker uncertainty on preschool-age children's and adults' detection of tonal signals in noise maskers. In Experiment 1 (signal uncertainty) the signal was randomly at 501 or 2818 Hz. The majority of the adult listeners showed a slight decrement in performance consistent with an ability to monitor both frequencies simultaneously. The majority of the children, however, showed no decrement in performance, suggesting that the children may not have focused attention at the signal frequency even when it was fixed. In Experiment 2 (masker uncertainty), random-frequency, random-level, tonal distracters were added to each interval of the 2 alternative-forced-choice (2afc) procedure. The effect of masker uncertainty was much larger than that of signal uncertainty. For most of the adult listeners and some of the children, the distracters produced higher thresholds (on average by 10 dB) and shallower psychometric function slopes. For most of the children, thresholds increased by 20 dB or more and psychometric functions were often nearly flat.
Comparison Between Clinician-Assisted and Fully Automated Procedures for Obtaining a Voice Range Profile
Authors: Titze Ingo R. , Wong Darrell , Milder Martin A. , Hensley Susan R. , Ramig Lorraine O.
Published: July 2014

A comparison was made between two methods of obtaining a voice range profile. One method was traditional, involving a clinician who gave instructions, motivated the subject to achieve the greatest intensity range, and determined when the goal was achieved. The second method was completely automated, involving the use of a videotape for instruction and a computer for elicitation and evaluation. Ten men and 10 women with normal voices participated as subjects in the study, and a counterbalanced design was used. Results indicated that there is no obvious preference for the use of either method, although considerable individual differences are noted.
Comparing Recognition of Distorted Speech Using an Equivalent Signal-to-Noise Ratio Index
Authors: Gordon-Salant Sandra , Fitzgibbons Peter J.
Published: July 2014

An index of equivalent performance in noise was developed to compare recognition in different forms of speech distortion. Speech-recognition performance of young and elderly listeners with and without hearing loss was evaluated for undistorted speech presented in quiet and noise, and for speech distorted by four time-compression ratios and by four reverberation times. The data obtained in noise on young subjects with normal hearing served to generate a normalized regression equation, which was used to convert percent-correct performance in different distortion conditions to equivalent performance for undistorted speech at a particular S/N ratio. Comparisons of the equivalent S/N ratios obtained in the various conditions allowed rank-ordering of speech recognition performance in different types of degradation. The data also show that age and hearing loss affect recognition of speech degraded by reverberation or time compression. However, age effects are evident primarily in the most severe distortion conditions. Recognition of undistorted speech in noise was affected by hearing loss but not by age. These findings support a hypothesis that stipulates that increased age produces a reduction in the functional S/N ratio.
A Phonologically Based Analysis of Misspellings by Third Graders With Disordered-Phonology Histories
Authors: Clarke-Klein Susan , Hodson Barbara Williams
Published: July 2014

Misspellings evidenced in written responses of third graders during administration of a battery containing 25 true words and 20 nonsense syllable items were analyzed phonologically. Children with histories of disordered phonologies evidenced more phonologically based deviations in their written misspellings than did their peers who had experienced normal phonological development. In addition, the children with disordered-phonology histories relied more on less productive spelling strategies and evidenced poorer phonological awareness skills than their peers with normal-phonology histories.
Adult Partner-Augmented Communication Input to Youth With Mental Retardation Using the System for Augmenting Language (SAL)
Authors: Sevcik Rose A. , Romski Mary Ann , Watkins Ruth V. , Deffebach Kim P.
Published: July 2014

The primary purpose of this study was to characterize the frequency and nature of augmented input that adult partners provided to 13 youth with mental retardation as they began to use the System for Augmenting Language (SAL). Analyses of youth-partner interactions revealed differences in the frequency with which home and school partners provided aug-mented input and in the manner and style of home and school partners' augmented input, particularly in directiveness and position of lexigram symbols within utterances. Overall, partners naturally provided augmented input in a manner likely to promote youth's learning of the SAL.
Orofacial Muscle Activity of Children Who Stutter: A Preliminary Study
Authors: Kelly Ellen M. , Smith Anne , Goffman Lisa
Published: July 2014

This study was a preliminary investigation of the relations between stuttering development and the maturation of speech motor processes. Electromyographic (EMG) activity was recorded from the orofacial muscles of children who stutter and their normally fluent peers during fluent and disfluent speech. Nine children who stutter (8 boys and 1 girl), ranging in age from 2:7 to 14:0, and 9 age- and sex-matched children who do not stutter were subjects. Pairs of surface EMG electrodes were placed on children’s faces overlying the anterior belly of the digastric (ABD), levator labii superior (ULIP), and orbicularis oris inferior (LLIP) muscles. Twenty segments of stuttered (for the children who stutter) and perceptually fluent speech were extracted from children’s conversational speech samples. Spectra of the amplitude envelopes of the EMG activity were computed. The 3 oldest children who stutter showed evidence of tremorlike oscillations of EMG activity in the 5 to 15 Hz range during stuttering in either ULIP, LLIP, or ABD muscles. The younger children who stutter and the children who do not stutter demonstrated primary spectral peaks in the 1 to 4 Hz range during stuttered and/or perceptually fluent speech. It is hypothesized that the emergence of tremorlike instabilities in the speech motor processes of children who stutter may coincide with aspects of their general neural maturation and with the development of stuttering.
Responsiveness of Male Adolescents With Mental Retardation to Input From Nondisabled Peers: The Summoning Power of Comments, Questions, and Directive Prompts
Authors: Wilkinson Krista M. , Romski Mary Ann
Published: July 2014

The expressive communication of individuals with cognitive impairments may be directly influenced by a partner’s input, because such individuals often have limited conversational skills. Sequential analyses of dyadic interactions examined the effects of input by 32 normally developing adolescents on responses by male subjects with mental retardation whose communication modes included augmented communication. Results suggested that (a) verbal prompts in the form of questions were significantly more likely to receive responses from subjects with mental retardation than directive prompts, (b) comments were significantly more likely to receive responses from subjects with retardation than were directive prompts, when the nondisabled peer was male, and (c) male subjects with mental retardation were more likely to respond to input from male peers than from females. These data suggest that questions facilitate naturally occurring conversations but underscore the importance of evaluating gender-related effects on interaction involving persons with severe cognitive and communication impairments.
Advanced Verb Form Production in Story Retelling
Authors: Sutter Judith C. L. , Johnson Cynthia J.
Published: July 2014

This study investigated the rate at which 60 elementary school children produced three advanced verb forms—past progressive, past perfect progressive, and past perfect—when asked to retell literate narratives, a discourse genre that originates from written prose and frequently contains these advanced verb forms. The three verb forms were embedded in nine story episodes and told to the children. The children were then asked to retell the stories. Verb form production by the children was scored as either “borrowed” or substituted spontaneous production. During their story-retelling episodes, the 6-, 7-, and 8-year-old children borrowed all verb forms under investigation from the stimuli stories. They significantly preferred to borrow the past progressive over the past perfect progressive and past perfect forms. Rate of verb form production by 8-year-old children was significantly higher than for the younger age groups. These data suggest that advanced verb form production is influenced by the children’s sensitivity to the type of narrative register (i.e., 1 st or 3rd person perspective), the propositional ability associated with narrative development, and the progressive meaning of the -ing suffix.
Reliability and Sensitivity of Paired Comparisons and Category Rating in Children
Authors: Eisenberg Laurie S. , Dirks Donald D.
Published: July 2014

Children’s subjective judgments of speech clarity using the methods of paired comparisons and category rating were evaluated in this investigation. Eighty children with normal hearing between the ages of 4 and 8 years judged the clarity of sentences that were systematically bandpass-filtered using conditions that increased intelligibility as estimated by the Articulation Index. Subjects were classified into four age groups (4-, 5-, 6-, and 7–8-year age groups) with 20 subjects per group. With use of materials and training methods suitable for children, judgments were obtained via the two psychophysical procedures (10 subjects per age group for each procedure). Results indicated that children 5 years of age and older were able to make reliable clarity judgments using either procedure; however, the method of paired comparisons was more sensitive than category rating in detecting differences between the bandpass-filtered conditions.
Effects of Distance on Vocal Intensity
Authors: Michael Deirdre D. , Siegel Gerald M. , Pick Herbert L.
Published: July 2014

The vocal response of speakers to change of distance from a listener is in dispute. Warren (1968) found that speakers obeyed the inverse square law when compensating for distance changes; that is, they decreased their vocal intensity by 6 dB when distance was halved. However, speakers in a study of Johnson, Pick, Siegel, Cicciarelli, and Garber (1981) changed their vocal intensity by much less than 6 dB. This study was an attempt to reconcile the conflicting results and to gain better understanding of what people know implicitly about the effects of distance on intensity. Speakers in the present study significantly changed their vocal intensity to compensate for changes in distance, but by a maximum of 2.46 dB. Possible reasons for the different results are discussed.
Initiation and Repair of Intentional Communication Acts by Adults With Severe to Profound Cognitive Disabilities
Authors: Brady Nancy C. , McLean James E. , McLean Lee K. , Johnston Susan
Published: July 2014

This study assessed the communication initiation and repair behaviors of 28 individuals with severe to profound mental retardation in a variety of experimental conditions. All of these individuals communicated through nonsymbolic gestures. The experimental procedures were devised to simulate the conditions that typically evoke two different types of initiations: comments and requests. Each subject initiation was followed by an experimenter response that indicated a communication breakdown to determine if and how these subjects would attempt to repair such breakdowns. Different indicators of communication breakdown were systematically varied in these scripted interactions, including explicit requests for repair (verbal and gestural) and implicit requests for repair (failure to respond or inappropriate response to the subject’s communication act). All subjects initiated at least one communication act, and all but three subjects repaired at least one communication act following a breakdown. Significantly more subjects initiated protoimperative than protodeclarative communication acts, despite equal opportunities for both types of acts. Across all conditions,
additions
were observed to occur significantly less often than
recasts
or
repetitions. There were
no significant differences in the number of subjects repairing communication following the different types of communication breakdown.
Comparison of Perioral Reflex Modulation in the Upper and Lower Lip
Authors: Barlow Steven M. , Bradford Paul T.
Published: July 2014

The spatiotemporal organization and specificity of the mechanically evoked, short latency penoral response (R1) was sampled from a group of normal adult humans. Perioral reflex activity was sampled during passive and active static force conditions in the presence of servo-controlled mechanical inputs to lip vermilion. Results confirmed that the sensorimotor apparatus of the lower face is very responsive to low level mechanical inputs and highly dependent on several factors including input site (upper vs. lower lip), amount of glabrous tissue stimulated (contactor array size), and task dynamics (passive vs. active subject-generated lip force). Arguments are presented to support the idea that several features of the peripheral sensory environment encoded by primary trigeminal afferents, including afferent gain, specificity, locus, and spatial summation, collectively provide inputs vital to higher order sensory relays in the development of a central representation and dynamic conformational map of perioral space. These sensorimotor features encoded by trigeminal afferents are presumed important for motor learning and maintenance of oromotor control during speech, suck, mastication and swallow, and gesture.
Speech Production in People Who Stutter: Testing the Motor Plan Assembly Hypothesis
Authors: Lieshout Pascal H.H.M. van , Hulstijn Wouter , Peters Herman F.M.
Published: July 2014

The main purpose of the present study was to test the hypothesis that persons who stutter, when compared to persons who do not stutter, are less able to assemble abstract motor plans for short verbal responses. Subjects were adult males who stutter and age- and sex-matched control speakers, who were tested on naming pictures and words, using a choice-reaction time paradigm for both tasks. Words varied in the number of syllables (1, 2, and 3 syllables) and, for the bisyllabic words, also in the number of consonants (one or more) at the onset of the second syllable. Measurements consisted of speech reaction times, word durations, and measures of relative timing of specific motor events in the respiratory, phonatory, and articulatory subsystems.

Results indicated that, in spite of longer speech reaction times for persons who stutter in comparison to control speakers, there was no interaction with word size, a finding that does not lend support to the abovementioned hypothesis. Word durations were found to be longer for persons who stutter, and, in addition, there was an interaction of group with word size. Both findings were associated with longer delays for persons who stutter in the onset of upper lip integrated electromyographic (IEMG) activity and thoracic compression, and a group effect on the order of upper lip and lower lip IEMG onset. Findings are taken to suggest the possibility that persons who stutter may use different motor control strategies to compensate for a reduced verbal motor skill, and although the nature of this reduced skill is unknown, it is speculated that it relates to the processes involved in the integration of sensory-motor information.
Spectral Distribution of Prosodic Information
Authors: Grant Ken W. , Walden Brian E.
Published: July 2014

Prosodic speech cues for rhythm, stress, and intonation are related primarily to variations in intensity, duration, and fundamental frequency. Because these cues make use of temporal properties of the speech waveform they are likely to be represented broadly across the speech spectrum. In order to determine the relative importance of different frequency regions for the recognition of Prosodic cues, identification of four Prosodic features, syllable number, syllabic stress, sentence intonation, and phrase boundary location, was evaluated under six filter conditions spanning the range from 200–6100 Hz. Each filter condition had equal articulation index (Al) weights, Al ½ 0.10; p(C)
isolated words
≈ 0.40. Results obtained with normally hearing subjects showed that there was an interaction between filter condition and the identification of specific Prosodic features. For example, information from high-frequency regions of speech was particularly useful in the identification of syllable number and stress, whereas information from low-frequency regions was helpful in identifying intonation patterns. In spite of these spectral differences, overall listeners performed remarkably well in identifying Prosodic patterns, although individual differences were apparent. For some subjects, equivalent levels of performance across the six filter conditions were achieved. These results are discussed in relation to auditory and auditory-visual speech recognition.
The Equilibrium Point Hypothesis and Its Application to Speech Motor Control
Authors: Perrier Pascal , Ostry David J. , Laboissière Rafael
Published: July 2014

In this paper, we address a number of issues in speech research in the context of the equilibrium point hypothesis of motor control. The hypothesis suggests that movements arise from shifts in the equilibrium position of the limb or the speech articulator. The equilibrium is a consequence of the interaction of central neural commands, reflex mechanisms, muscle properties, and external loads, but it is under the control of central neural commands. These commands act to shift the equilibrium via centrally specified signals acting at the level of the motoneurone (MN) pool. In the context of a model of sagittal plane jaw and hyoid motion based on the λ version of the equilibrium point hypothesis, we consider the implications of this hypothesis for the notion of articulatory targets. We suggest that simple linear control signals may underlie smooth articulatory trajectories. We explore as well the phenomenon of intra-articulator coarticulation in jaw movement. We suggest that even when no account is taken of upcoming context, that apparent anticipatory changes in movement amplitude and duration may arise due to dynamics. We also present a number of simulations that show in different ways how variability in measured kinematics can arise in spite of constant magnitude speech control signals.
How Children Learn to Organize Their Speech Gestures: Further Evidence From Fricative-Vowel Syllables
Authors: Nittrouer Susan , Studdert-Kennedy Michael , Neely Stephen T.
Published: July 2014

Previous studies with fricative-vowel (FV) syllables have shown that the difference in overall spectrum between fricatives is less in children’s speech than in that of adults, but that fricative noises show greater differences in the region of the second formant (F
2
) as a function of the upcoming vowel than those of adults at corresponding points in the fricative. These results have been interpreted as evidence that children produce fricatives that are not as spatially differentiated as those of adults and that children initiate vowel gestures earlier during syllable production than adults do (Nittrouer, Studdert-Kennedy, & McGowan, 1989). The goals of the present study were (a) to replicate the previous age-related difference for F
2
with FV syllables; (b) to test the alternative interpretation that age-related differences in fricative F
2
reflect age-related differences in vocal-tract geometry; (c) to determine whether age-related differences in F
2
(and so, by inference] in articulatory organization) might extend beyond the syllable boundaries, perhaps into the schwa of a preceding unstressed syllable; and (d) to determine if gestures other than fricative gestures show less spatial differentiation in children’s than in adults’ speech. To these ends, F
2
frequencies were measured in schwa-fricative-vowel utterances (consisting of the fricatives /s/ and /ʃ/ and of the vowels /i/ and /ɑ/
)
from 40 speakers (10 each of the ages of 3, 5, 7 years, and adults) at three locations (for the entire schwa, for 10 ms of fricative noise centered at 30 ms before voicing onset, and for 10 pitch periods from vocalic center). Results of several analyses supported four conclusions: (a) the earlier finding was replicated; (b) age-related differences in vocal-tract geometry could not explain the age-related difference in vowel effects on fricative noise; (c) children master intersyllabic gestural organization prior to intrasyllabic gestural organization; and (d) unlike fricative gestures, children’s vowel gestures are more spatially distinct than those of adults.
Persistence of Non-Standard Dialect in School-Age Children
Authors: Isaacs Gale J.
Published: July 2014

This study investigated the persistence of non-standard dialect production among 114 African American and White children in grades 3,5, and 7. A dialect shift premise suggests that a large and uniform decline in dialectal features occurs in the language of school-age children. Three experimental tasks were administered. The results indicated that dialect awareness and discrimination increased as grade in school increased; a dialect shift occurred between grades 3 and 5; non-standard dialect production and comprehension of standard dialect were not associated; and that there was no difference in non-standard dialect production among African American and White students.
Speaking Fundamental Frequency Characteristics of White, African American, and Hispanic Kindergartners
Authors: Awan Shaheen N. , Mueller Peter B.
Published: July 2014

Speech samples from groups of White, African American, and Hispanic kindergarten-age children were compared on measures of mean speaking fundamental frequency (F
o
), maximum and minimum speaking F
o
, pitch sigma, and speaking range (in semitones). Results indicate that there are significant differences between racial groups on measures of mean speaking F
o
and speaking range. In particular, the Hispanic children were observed to have increased mean speaking F
O
S in comparison with the African American children and reduced speaking ranges as compared to both African American and White racial groups. Results indicate that the speech-language pathologist must exercise discretion when assessing the speaking F
o
characteristics (particularly mean speaking F
o
and speaking range) of children from different racial groups.
Reflex Responses of Lip Muscles in Young and Older Women
Authors: Wohlert Amy B.
Published: July 2014

The perioral reflex in response to innocuous mechanical stimulation of the lip vermilion was studied in 20 young and 20 older women. Responses to stimuli at the right and left sides of both the upper and lower lips were recorded. Results show significant specificity of response, especially for upper lip sites. Reflex response at the site of stimulation was greatest in amplitude and shortest in latency, followed by response at sites ipsilateral to the site of stimulation. Younger subjects showed greater localizing tendency than older subjects.

Stimulation was significantly less likely to produce a reflex response in the older group. When reflex responses did occur, they were significantly lower in amplitude and longer in latency than the responses of the younger group. Nonetheless, reflex responses were common in both groups, with responses at the site of stimulation occurring 78% of the time in older women and 90% of the time in younger women. Every participant showed at least one reflex response to lip stimulation. Results suggest decreasing complexity of synaptic drive to the perioral system in old age but also show that reflexive response does not deteriorate completely, remaining an available element for motor control in normal older women.
Genetics of Stuttering
Authors: Yairi Ehud , Ambrose Nicoline , Cox Nancy
Published: July 2014

The fact that stuttering runs in families has been documented over a long period and has led to speculations and research about the role of a genetic component to this disorder. Although the genetic factor cannot be proved by familial aggregation and twin studies alone, such research has continued to provide support for a relationship between stuttering and genetics. The purposes of this article are to review and critique the research in this area. The article first assesses research methodologies that have been employed in familial studies of stuttering. It proceeds to review and critique incidence, twin, and aggregation studies. In addition, it includes sections on subgroups, genetic models of stuttering, and implications for future research as well as for clinical work. With a focus on improved methodology and recent findings, a current perspective on our knowledge of the genetic component to stuttering is provided. Among other conclusions, the article emphasizes that failure to consider epidemiologic factors has probably biased previous results regarding the genetics of stuttering. New preliminary data also appear to provide evidence that spontaneous recovery and chronicity are influenced by genetic factors. Generally, however, the review of incidence and twin studies, as well as of evidence for the various inheritance models, confirms previous conclusions about the interaction between genetic and environmental factors in stuttering.
A Longitudinal Study of Stuttering in Children
Authors: Yairi Ehud , Ambrose Nicoline
Published: July 2014

It has come to our attention that minor errors occurred in Table 3 on p. 759 of the Yairi and Ambrose article, "A Longitudinal Study of Stuttering in Children: A Preliminary Report," which appeared in the August 1992 issue (Vol. 35, pp. 755–760). A revised version of the table appears below that includes both the original values and the corrected values (in boldface). As can be seen, the differences are indeed minor. The changes do not affect the reported patterns or level of statistical significance. In the untreated group, 7 or 78% recovered by 24 months post-onset and 1 additional subject recovered later, making a total recovery rate of 89%, with 11% persistent. In the treated group, 11 or 61% recovered by 24 months post-onset and an additional 5 recovered later, again totalling 89% recovery and 11% persistent. These data do not in any way indicate that treatment is not beneficial nor that it has no effect but simply that success rates for treated individuals must take spontaneous recovery into account. We regret the error.
Linear Predictive Coding Parameter Manipulation/Synthesis of Incorrectly Produced /r/
Authors: Shuster Linda I.
Published: July 2014

This study describes the manipulation and synthesis of LPC parameters to edit incorrectly produced utterances. In particular, it shows that formant frequencies can be manipulated to produce a consistent and reliable change in perception. It also demonstrates that this method can be used to produce quality synthesis of high-pitched voices.
Vowel Perception in Children With and Without Language Impairment
Authors: Stark Rachel E. , Heinz John M.
Published: July 2014

Twenty-four children with language impairment (LI) and 22 children without language impairment (LN) participated in a study of discrimination, identification, and serial ordering of the highly dissimilar vowels /a/ versus /i/, and the highly similar vowels /ε/ versus /æ/. The vowel pairs were presented to the subjects in long- and short-duration sets. Both groups had greater difficulty in identifying /ε/ versus /æ/ than /a/ versus /i/. Neither group had greater difficulty with the short- than the long-duration vowel sets. The LI children were less efficient than the LN in identifying /a/ versus /i/, but could identify them accurately. They were significantly less accurate than the LN in identifying /ε/ versus /æ/. The majority of the children who could identify the /a/ and /i/ vowels were able to order them serially as well, although this second task appeared to be more difficult than identification. Fewer LI than LN children were able to proceed to the serial ordering task with /ε/ and /æ/. The children who could not identify the vowels within a set were almost always able to discriminate them. It was concluded that LI children have an auditory perceptual learning deficit and consequently a less robust central representation for steady state vowels than LN.
Effect of Visual and Inferential Variables on Scene Descriptions by Right-Hemisphere-Damaged and Non-Brain-Damaged Adults
Authors: Myers Penelope S. , Brookshire Robert H.
Published: July 2014

This study investigated the effects of visual and inferential complexity on the pictured scene descriptions of right-hemisphere-damaged (RHD) and non-brain-damaged (NBD) adults. The number and accuracy of noun phrases generated by both groups were significantly affected by the inferential complexity of pictured scenes, but not by their visual complexity (as measured by the number of objects and amount of object embedding in the scenes). RHD subjects, particularly those with high levels of neglect, were significantly impaired relative to the NBD subjects in generating accurate inferences from the pictures, but not in their ability to recognize and identify pictured elements.
Mechanosensory Modulation of Perioral Neuronal Groups During Active Force Dynamics
Authors: Andreatta Richard D. , Barlow Steven M. , Biswas Amitava , Finan Donald S.
Published: July 2014

The spatiotemporal organization of the mechanically evoked perioral sensorimotor response was sampled from five normal females using a custom-designed linear motor operating under force feedback. Electromyographic activity was sampled from the superior and inferior segments of the orbicularis oris muscle during the production of a visually guided ramp-and-hold lip-rounding task. Brief mechanical inputs of approximately 0.45 N delivered to the left upper lip during the ramp-and-hold task produced a composite myogenic response characterized by phases of excitation and suppression. Modulation of the primary excitatory component (R1) of the mechanically evoked perioral response was found to be highly dependent upon the rate of force recruitment (1 N/s vs. 4 N/s) and the phase of force recruitment (20% vs. 50% vs. 80% of 1 N end-point force). Modulation of later occurring inhibitory (S1) and excitatory (R2) potentials were also found to be dependent upon differences in the rate and phase of force recruitment. The organization of the perioral sensorimotor response is considered in relation to speech motor control and the dynamic organization of neuronal groups subserving perioral sensorimotor activity.
Effects of Length and Linguistic Complexity on Temporal Acoustic Measures in Apraxia of Speech
Authors: Strand Edythe A. , McNeil Malcolm R.
Published: July 2014

The purpose of this study was to examine the effects of varying length and linguistic utterance types on temporal acoustic characteristics of the imitative speech of apraxic speakers. Vowel duration and two between-word segment durations were examined during the production of three response types: words, word-strings, and sentences. Three length conditions were studied in words, two length conditions for word-strings, and three length conditions for sentences, yielding eight experimental conditions. Apraxic speakers exhibited significantly longer vowel and between-word segment durations than control speakers in all conditions. Apraxic speakers consistently produced longer vowel and between-word segment durations in sentence contexts than in word contexts. Further, intrasubject and intersubject variability for between-word segment durations were substantially greater for the apraxic speakers in sentences compared to word conditions, whereas control speakers exhibited greater homogeneity in sentence production. The differences in duration and variability in sentence production versus word or word-string production imply different mechanisms for executing motor programs for varying linguistic stimuli.
Reliability and Stability of Various Hearing-Aid Outcome Measures in a Group of Elderly Hearing-Aid Wearers
Authors: Humes Larry E. , Halling Dan , Coughlin Maureen
Published: July 2014

Twenty elderly persons with hearing impairment were fit with binaural in-the-ear hearing aids and followed for a 6-month period post-fit. Several hearing-aid outcome measures were obtained at 0, 7, 15, 30, 60, 90, and 180 days post-fit. Outcome measures included (a) objective measures of benefit obtained with nonsense-syllable materials in quiet (CUNY Nonsense Syllable Test, NST) and sentences in multitalker babble (Hearing in Noise Test, HINT); (b) two subjective measures of benefit, one derived from pre-fit/post-fit comparisons on a general scale of hearing handicap (Hearing Handicap Inventory for the Elderly, HHIE) and the other based on a subjective scale of post-fit hearing-aid benefit (Hearing Aid Performance Inventory, HAPI); (c) a questionnaire on hearing-aid satisfaction; (d) an objective measure of hearing-aid use; and (e) a subjective measure of hearing-aid use. Reliability and stability of each measure were examined through repeated-measures analyses of variance, a series of test-retest correlations, and, where possible, scatterplots of the scores against their corresponding 95% critical differences. Many of the measures were found to be both reliable and stable indicators of hearing-aid outcome.
Treatment Efficacy
Authors: Holland Audrey L. , Fromm Davida S. , DeRuyter Frank , Stein Margo
Published: July 2014

This article presents a brief overview of aphasia, followed by a summary of research studies and program evaluation data addressed to answering the question of the efficacy of treatment for aphasia. Selected studies are reviewed in terms of the quality of evidence they present. In addition, a number of questions that remain unanswered are also presented. Several tables, designed to provide clarifying information concerning several aspects of research design (number and types of patients studied, examples of well-designed small-group or single-subject studies, clinical techniques for which efficacy data are available), are included. The conclusion of this review is that, generally, treatment for aphasia is efficacious.