bluuebunny/crossref_metadata_2025 huggingface dataset:
Neural Drive to Muscles in Stuttering
Authors: Smith Anne
Published: July 2014

EMG recordings were made from muscles of the jaw, lip, and neck during speech of 10 stutterers and 10 nonstutterers. One-second records of disfluent behaviors of stutterers and of fluent speech of the normal speakers were analyzed by computing cross correlations between all possible muscle pairs and spectra for each muscle channel. The cross correlation analysis indicated that for both the disfluent behavior of stutterers and the fluent speech of nonstutterers, jaw muscles (including antagonistic pairs), lip muscles, and neck muscles tend to be coactivated. Thus, no dramatic differences in muscle activation patterns were revealed in the correlational analysis. In contrast, spectral analysis revealed differences between muscle activity during disfluent behavior and fluent speech. During disfluencies the muscles of 6 of the stutterers showed large, rhythmic oscillations in the frequency range of 5 to 12 Hz. Large oscillations were not observed in this frequency range in the muscle activity of normal speakers. The oscillations in muscle activity during disfluencies generally occurred at the same frequency in the various muscle systems studied. These results suggest that diverse muscles are subject to common oscillatory synaptic drive during disfluent behaviors and that this drive is disruptive to speech production. A reasonable speculation is that the disruptive oscillatory drive is produced by tremorogenic mechanisms.
Temporal-Phonemic Processing Skills in Adult Stutterers and Nonstutterers
Authors: Meyers Susan C. , Hughes Larry F. , Schoeny Zahrl G.
Published: July 2014

The purpose of this study was to investigate the hypothesis that stuttering is related to a dysfunction in auditory temporal processing. The performance of 20 adult male stutterers and 20 matched nonstutterers was studied using two auditory processing tasks. The subjects listened to stimuli with differential onset asynchronies during temporal order judgment (TOJ) and dichotic listening tasks. Stutterers and nonstutterers were not significantly different at judging which ear received the stimulation first (TOJ task) at varying stimulus onset asynchronies (SOAs). During the dichotic listening task, stutterers made significantly fewer double-correct responses (correct report for both stimuli in a dichotic pair) than nonstutterers. The stuttering subjects correctly classified one of the syllables in a pair (single-correct response) more frequently than normal controls on the dichotic listening task. These findings suggest that SOAs as a temporal parameter do not differentiate the performance of the two groups. The more difficult auditory processing task (dichotic identification) showed a significant difference in the performance of the stutterers versus nonstutterers.
Auditory Time Constants for Off-Frequency Forward Masking in Normal-Hearing and Hearing-Impaired Listeners
Authors: Nelson David A. , Pavlov Rosemary
Published: July 2014

Previous research has shown that frequency-specific estimates of auditory time constants for recovery from short-term adaptation can be made using a fixed-probe forward-masking procedure (Nelson & Freyman, 1987) if the masker and the probe stimuli are at the same frequency. This study examines the validity of time-constant estimates for off-frequency forward-masking conditions in which the masker frequency is below (900 Hz) or above (1100 Hz) the probe frequency (1000 Hz). Fixed-probe-level temporal masking functions were obtained from four normal-hearing and four hearing-impaired listeners. Auditory time constants were estimated with iterative least-squares procedures to derive parameter values for an exponential model of recovery from forward masking. After appropriate corrections were made for attenuation to the maskers provided by the auditory filter centered at the probe frequency, recovery from forward masking produced by either off-frequency or on-frequency maskers could be described by a single time constant. That time constant was around 50 ms in normal-hearing listeners and was larger in those hearing-impaired listeners who demonstrated moderate hearing loss at the probe frequency.
The Selection of "Fluent" Samples in Research on Stuttering
Authors: Finn Patrick , Ingham Roger J.
Published: July 2014

The characteristics of stutterers' fluency has been the object of much research in recent years, but it is not always clear what the term "fluency" refers to in this research. This paper reviews the concept of fluency and considers the ways in which it has been employed in research on stuttering. The methods that have been used to identify fluent intervals in stutterers' speech are reviewed along with their reliability and validity. It is concluded that there is an urgent need to clarify the referent for fluency in such studies, and to develop procedures for measuring and quantifying fluency. Additional avenues for research are also discussed.
Empirical Tests Demonstrating Two Coexisting Sources of Tinnitus
Authors: Penner M. J.
Published: July 2014

Empirical tests for a relation between tinnitus and spontaneous otoacoustic emissions (SOAEs) have been previously presented (Penner & Burns, 1987). Modification of these tests, however, is necessary for the special case reported here in which a female subject has tinnitus consisting of an annoying SOAE in the right ear and tinnitus unrelated to SOAEs in the left ear. This case is of interest because it provides a forum for extending the tests of Penner and Burns (1987) and because the extended tests can be used to prove that one subject's tinnitus can have two distinct sources.
The Reliability of Type-Token Ratios for the Oral Language of School Age Children
Authors: Hess Carla W. , Haug Holly T. , Landry Richard G.
Published: July 2014

This study investigated the alternate forms reliability of four type-token ratios (TTRs) of oral language samples obtained from 52 elementary school children (9 through 12 years of age). The four TTRs included the basic type-token ratio, the corrected type-token ratio, the root type-token ratio, and the bilogarithmic type-token ratio. Language samples of 600 words were segmented into 50-word, 100-word, and 200-word samples. Within each TTR measure, there were no significant differences among the means for samples of the same size, but all means for a given sample size differed significantly from the means of all other sample sizes. Further, for samples of the same size the reliability coefficients calculated for each TTR measure were neither consistent nor significant. These findings indicate that under the conditions of the present study TTRs are not comparable when calculated for different sample sizes ranging from 50 to 600 words, and further, that they are not reliable measures of the language performance of individual elementary school children from regular classrooms for language samples of 50 to 200 words.
Unusual Phonological Behavior and the Avoidance of Homonymy in Children
Authors: Leonard Laurence B. , Schwartz Richard G. , Allen George D. , Swanson Lori A. , Loeb Diane Frome
Published: July 2014

Young children sometimes make use of unusual phonological patterns even when they already possess the appropriate sound or a suitable substitute in their phonological systems. In this investigation, we attempted to determine whether in such instances unusual sound changes enable children to avoid potential homonymy with other words in their lexicons. Novel words were presented to children, half serving as potential homonyms, half as unlikely homonyms. The children's acquisition of these words was monitored. For a group of normally developing children, unusual sound changes were found to be more frequent in the words with the potential for homonymy. In contrast, a group of children with specific language impairment showed the same degree of unusual usage for both types of words. The findings suggest that children with specific language impairment are especially limited in their ability to capitalize on the phonetic regularities of the language.
Is the Syntax Development of Dysphasic Children Deviant and Why? New Findings to an Old Question
Authors: Grimm Hannelore , Weinert Sabine
Published: July 2014

The present study addresses three main issues: First, it considers whether the syntax development of dysphasic preschoolers is adequately described as being a purely quantitative retardation or whether there are qualitative differences as well. Second, the suggestion put forward by Grimm (1987) that the syntactic deficits of dysphasic children result from deficient language processing strategies is further explored. Third, it asks whether the language deficits are related to specific structural and interactional aspects of the language input.

We examined two groups of children with comparable levels of language development: 8 dysphasic children, ages 3:9 to 4:8 years, and 8 control children, ages 2:1 to 2:11 years, who showed normal language development. The empirical evidence suggested that the dysphasic children’s syntax development was not only delayed but also deviant, and that the children’s deviant syntax structures were the result of insufficient language processing and could not be traced back to structural characteristics of the sentences used by their mothers.
Recognition of Voiceless Fricatives by Normal and Hearing-Impaired Subjects
Authors: Zeng Fan-Gang , Turner Christopher W.
Published: July 2014

The purpose of this study was to investigate the sufficient perceptual cues used in the recognition of four voiceless fricative consonants [s, f, θ, ∫] followed by the same vowel [i:] in normal-hearing and hearing-impaired adult listeners. Subjects identified the four CV speech tokens in a closed-set response task across a range of presentation levels. Fricative syllables were either produced by a human speaker in the natural stimulus set, or generated by a computer program in the synthetic stimulus set. By comparing conditions in which the subjects were presented with equivalent degrees of audibility for individual fricatives, it was possible to isolate the factor of lack of audibility from that of loss of suprathreshold discriminability. Results indicate that (a) the frication burst portion may serve as a sufficient cue for correct recognition of voiceless fricatives by normal-hearing subjects, whereas the more intense CV transition portion, though it may not be necessary, can also assist these subjects to distinguish place information, particularly at low presentation levels; (b) hearing-impaired subjects achieved close-to-normal recognition performance when given equivalent degrees of audibility of the frication cue, but they obtained poorer-than-normal performance if only given equivalent degrees of audibility of the transition cue; (c) the difficulty that hearing-impaired subjects have in perceiving fricatives under normal circumstances may be due to two factors: the lack of audibility of the frication cue and the loss of discriminability of the transition cue.
Glottal Closure and Perceived Breathiness During Phonation in Normally Speaking Subjects
Authors: Södersten Maria , Lindestad Per-Åke
Published: July 2014

Glottal closure and perceived breathiness were evaluated in 9 female and 9 male normally speaking subjects ranging in age from 20 to 35 years. Phonations of the vowel /i:/ at three loudness and pitch levels were performed. The degree of glottal closure was judged by speech clinicians from video-fiberstroboscopic recordings. Later they rated the degree of perceived breathiness both in the vowels recorded during the fiberscopy and in separately tape-recorded vowels. Intra- and interjudge reliabilities were satisfactory. The degree of incomplete glottal closure and the degree of perceived breathiness were significantly higher for the women than for the men. For both sexes, the degree of incomplete closure and perceived breathiness increased significantly as an effect of decreased loudness. Neither the degree of closure nor the perceived breathiness were significantly affected by changes in pitch or by interaction effects. It was concluded that incomplete glottal closure of the posterior parts of glottis should be regarded as normal primarily in women and that loudness should be taken into consideration when studying glottal closure and breathiness.
The Effects of a Tracheostoma Valve on the Intelligibility and Quality of Tracheoesophageal Speech
Authors: Fujimoto Pamela A. , Madison Charles L. , Larrigan Lynn B.
Published: July 2014

In a listening experiment, speech samples obtained from a tracheoesophageal speaker were judged for intelligibility and general quality by inexperienced and experienced listeners. The speaker produced the speech samples using finger occlusion of the stoma and using a tracheostoma valve. Results showed no significant differences in intelligibility of speech between occlusion conditions for single words, 5-word sentences, and 10-word sentences. Conversational intelligibility was judged to be adversely affected by the tracheostoma valve, though quality of speech was not. No significant differences were found between the judgments of inexperienced and experienced listeners.
Lip Muscle EMG Responses to Oral Pressure Stimulation
Authors: McClean Michael D.
Published: July 2014

Sinusoidal intraoral pressure changes having peak-to-peak amplitudes of 2–6 cmH20 were applied at frequencies of 2–14 Hz. Reflex responses were observed in the lip muscle EMG of all 6 subjects tested. Across subjects, the phase shift of EMG responses varied in a linear manner with stimulus frequency. This suggests that responses were mediated over a reflex pathway having a relatively fixed response latency. Step-like changes in oral pressure produced a consistent excitatory response having a latency of 30–35 ms. The fact that reflexes may be elicited in lip muscles with oral pressure changes similar to those occurring in speech increases the likelihood that mechanoreceptor responses to intraoral pressure changes are involved in sensorimotor integration for speech production.
The Relation Between Interangle Span and In Vivo Resultant Force in the Perioral Musculature
Authors: Barlow Steven M. , Muller Eric M.
Published: July 2014

The variable nature of the perioral system as a force generator is due, in large part, to differences in the spatial arrangement and degree of muscle representation in this region. This fact requires careful consideration when attempting to compare select properties of force dynamics among individual subjects in health and disease. The objective of the present study was to determine the relation between an indirect measure of muscle length (interangle span) and in vivo resultant force in the perioral region of normal adult subjects. Perioral force associated with the maximum voluntary contraction (MVC) was found to increase systematically with increases in the span between the load sensitive cantilevers positioned between the corners of the mouth. The active force component of the MVC was significantly greater for male than female subjects, whereas passive forces were equal. Active force is discussed in relation to rest positions of the oral opening and the assessment of the force operating range for speech and other oromotor behaviors in health and disease.
An Application of the Articulation Index to Hearing Aid Fitting
Authors: Rankovic Christine M.
Published: July 2014

The application of the articulation index (Al) model to the fitting of linear amplification was evaluated for 12 subjects with sensorineural hearing loss. Comparisons were made of amplification characteristics specified by the NAL (Byrne & Dillon, 1986) and POGO (McCandless & Lyregaard, 1983) prescriptions, as well as a procedure that attempted to maximize the Al (AlMax). For all subjects, the relationship between percent-correct scores on a nonsense syllable test and Als was monotonic for the two prescriptions, indicating that the Al was effective for comparing conditions typical of those recommended clinically. However, subjects having sloping high-frequency hearing losses demonstrated nonmonotonicity due to poor performance in the AlMax condition. For these subjects, the AlMax condition required much more gain at high than at low frequencies, circumstances that Skinner (1980) warned will cause less-than-optimal performance for individuals having sloping high-frequency hearing loss.
Laryngeal Electromyographic Activity in Adductor and Abductor Spasmodic Dysphonia
Authors: Watson Ben C. , Schaefer Steven D. , Freeman Frances J. , Dembowski James , Kondraske George , Roark Rick
Published: July 2014

Vocal symptoms in spasmodic dysphonia (SD) range from strain-strangle phonation and glottal-stop phonatory breaks of adductor SD to breathy phonation and aspirate phonatory breaks of abductor SD. Many SD subjects show both symptom types. Heterogeneity in vocal symptoms contributes to controversy surrounding the etiology(s) of SD. Acoustic/perceptual analyses of vocal symptoms are inconclusive in resolving this controversy. This investigation moves the search for distinguishing features of adductor and abductor SD to the level of neuromuscular control and analysis of intrinsic laryngeal muscle (adductor and abductor) activity. Subjects rated perceptually as primarily adductor or abductor SD sustained production of vegetative gestures and isolated speech sounds (/i/ and /s/). Qualitative and quantitative analyses of electromyographic signals recorded from thyroarytenoid (TA) failed to differentiate SD subjects by symptom type. Analysis of TA and posterior cricoarytenoid (PCA) activity in one abductor SD revealed high levels in both muscles during production of the voiced vowel. Data suggest that a possible explanation for symptom heterogeneity in SD is the relation between disrupted neuromotor input to laryngeal muscles and reflexive or conscious compensations constrained by laryngeal biomechanics.
A Continuous-Flow Model for Phonatory Reaction Time
Authors: Ferrand Carole , Blood Gordon W. , Gilbert Harvey R.
Published: July 2014

The purpose of this study was to validate a proposed continuous-flow model of phonatory reaction time by investigating the temporal order of selected laryngeal and neurophysiological events involved in a phonatory reaction time task. Ten normal speakers participated in a phonatory reaction time task. Laryngeal positioning movements prior to vocal fold closure (laryngeal shift) and onset of vocal fold vibration (acoustic onset) were recorded with an electroglottograph. P300 brain potentials were collected simultaneously, and they served as an index of a central process underlying reaction time. The obtained temporal ordering of laryngeal shift, P300, and acoustic onset supported a continuous-flow model of phonatory reaction time. Use of this model might yield information that is more accurate in explaining physiological function and more precise in describing temporal patterning than the serial model.
Language and Gesture in Late Talkers
Authors: Thal Donna , Tobias Stacy , Morrison Deborah
Published: July 2014

A 1-year follow-up of relationships between language and symbolic gesture in 10 children with delayed onset of early lexical skills (Thal & Bates, 1988a) is reported Original data are reevaluated in light of new knowledge about which late talkers continued to be significantly delayed 1 year later (truly delayed) and which ones had “caught up” (late bloomers) Results showed that all 4 children who were truly delayed at follow-up had been delayed in language comprehension at the first visit, but the 6 late bloomers had been at the same level as their age-matched controls. In addition, truly delayed late talkers had been significantly poorer on all of the gesture tasks than late talkers who caught up
Consistency of Electroacoustic Characteristics Across Components of FM Systems
Authors: Thibodeau Linda M. , Saucedo Kathryn A.
Published: July 2014

In the absence of national or international electroacoustic standards for the evaluation of Frequency Modulated (FM) amplification systems, it becomes important to know the variability one may expect across similar models. Evaluation of thirty FM systems of the same model obtained from three different educational sites was performed to determine the variability that may occur as a result of the receiver, lapel microphone, or neckloop. There was a range as great as 20 dB in high frequency average saturation sound pressure level and equivalent input noise across receivers, lapel microphones, and neckloops. These results highlight the need for regular electroacoustic monitoring of not only the FM transmitter and receiver, but also the individual components, such as the lapel microphone and the neckloop.
A Study of Nasometric Values for Normal Nasal Resonance
Authors: Seaver Earl J. , Dalston Roger M. , Leeper Herbert A. , Adams Larry E.
Published: July 2014

It was the purpose of this study to obtain nasalance values for a large number of normal adult subjects speaking a variety of dialects of English. The Nasometer was used to measure the amount of nasal acoustic energy in the speech of 148 normal adults from four geographical regions of North America. Means and standard deviations for the nasalance and deviation scores are presented for each of three different reading passages. The Mid-Atlantic speakers were found to have significantly higher nasalance scores on all three reading passages. In addition, the female subjects had significantly higher nasalance scores on the Nasal Sentences. These differences are discussed with regard to potential reasons for their existence implications for understanding velopharyngeal function in normal and abnormal speakers.
Generalization Patterns Associated With Training Least Phonological Knowledge
Authors: Williams A. Lynn
Published: July 2014

This study examined the relationship between productive phonological knowledge and generalization learning patterns in phonologically disordered children. Nine functionally misarticulating children (ages 3:8–5:9) were trained on aspects of their phonological systems that were characterized as inventory constraints that constituted “least phonological knowledge” in relation to the adult sound system (Elbert & Gierut, 1986). The misarticulated sounds were trained in the context of consonant clusters. Although all the subjects exhibited equivalent levels of phonological knowledge on the same misarticulated sounds and identical training was provided, three different learning patterns were observed. Results are discussed with regard to the characterization of phonological knowledge in underlying representations that are depicted as “non-adult-like” or incorrect relative to the target sound system. Implications for clinical assessment are discussed.
Comparison of Idiom Comprehension of Normal Children and Children With Mental Retardation
Authors: Ezell Helen K. , Goldstein Howard
Published: July 2014

This study compared the comprehension of 20 idioms of normal children with children exhibiting mild mental retardation. Sixty-six children comprised three groups: normal 9-year-olds, 9-year-old children with mild mental retardation, and younger normal children matched with the mentally retarded children by receptive vocabulary age. The assessment included both literal and idiomatic contexts with accompanying picture stimuli. The three groups demonstrated high accuracy with the literal contexts. On the idiomatic contexts, the normal children comprehended significantly more idioms than the children with mental retardation, and the mentally retarded children performed significantly better than the younger normal children.
Interobserver Reliability Using the Phonetic Level Evaluation With Severely and Profoundly Hearing-Impaired Children
Authors: Shaw Stephanie , Coggins Truman E.
Published: July 2014

This study examines whether observers reliably categorize selected speech production behaviors in hearing-impaired children. A group of experienced speech-language pathologists was trained to score the elicited imitations of 5 profoundly and 5 severely hearing-impaired subjects using the Phonetic Level Evaluation (Ling, 1976). Interrater reliability was calculated using intraclass correlation coefficients. Overall, the magnitude of the coefficients was found to be considerably below what would be accepted in published behavioral research. Failure to obtain acceptably high levels of reliability suggests that the Phonetic Level Evaluation may not yet be an accurate and objective speech assessment measure for hearing-impaired children.
Speech Deterioration in Amyotrophic Lateral Sclerosis
Authors: Kent Raymond D. , Sufit Robert L. , Rosenbek John C. , Kent Jane F. , Weismer Gary , Martin Ruth E. , Brooks Benjamin R.
Published: July 2014

Few detailed reports have been published on the nature of speech and voice changes during the course of amyotrophic lateral sclerosis (ALS). The subject of this case study is a woman who was diagnosed as having ALS with bulbar signs at the age of 53. Speech intelligibility, pulmonary function, and selected speech and voice functions were tested during an approximately 2-year course of her disease. Over this period, her speech intelligibility, as measured by a multiplechoice word identification test, declined from 98% to 48%. Phonetic features that were most affected during the intelligibility decline included voicing contrast for syllable-initial and syllablefinal consonants, place of articulation contrasts for lingual consonants, manner of articulation for lingual consonants, stop versus nasal manner of production, features related to the liquid consonants, and various features related to syllable shape. An acoustic measure, average slope of the second-formant frequency, declined in association with the intelligibility reduction and is thought to reflect the loss of lingual motoneurons. Her pulmonary function also declined over the observation interval, with particularly severe reduction in measures of air flow. Oral diadochokinesis and measures of vocal function (including jitter, shimmer, and signal-to-noise ratio) were highly variable across test sessions. These results are discussed in terms of the challenges they present to sensitive assessment of change and to management of the communication disability in ALS.
Conversational Responsiveness of Speech- and Language-Impaired Preschoolers
Authors: Hadley Pamela A. , Rice Mabel L.
Published: July 2014

The purpose of this study was to describe preschoolers’ conversational responsiveness in an integrated classroom setting. Variables of primary interest were the types of responses as a function of the conversational partner. The children were categorized according to language ability: normally developing, marginal (children previously diagnosed as language or speech impaired, but now functioning within the normal range), language impaired (LI), and speech impaired (SI). They were observed during free play. Differences in response types were apparent between groups with both adult and peer partners. LI and SI children were ignored by their peers and responded less often when a peer initiated to them. Hence, they participated in proportionately fewer peer interactions. These results suggest that peer interaction difficulties may be concomitant consequences of early speech and language impairments. Clinical implications for verbal interactive skill intervention, particularly with peers in classroom settings, are discussed
Frequency Discrimination as a Function of Signal Frequency and Level in Normal-Hearing and Hearing-Impaired Listeners
Authors: Freyman Richard L. , Nelson David A.
Published: July 2014

Frequency difference limens (DLFs) for pure tones were obtained over a wide range of frequencies and levels from 7 normal-hearing subjects and 16 ears of 12 listeners with sensorineural hearing losses. The normal data were fitted with a general prediction equation. Variability of the data around the DLFs estimated by the equation was quantified and used to evaluate the DLFs from the hearing-impaired listeners. The majority of DLFs from impaired listeners were poorer than one standard deviation above the estimates of the normal equation at all frequencies and sensation levels (SLs). The portion of the equation concerned with sensation level was fitted to each listener’s data at each frequency. The slopes of these functions indicated that, on average, the rate of improvement of the DLF with sensation level was similar in the two groups of subjects. These results suggest that it would be reasonable to compare DLFs from normal-hearing and hearing-impaired listeners at equivalent sensation levels. The intercepts of the DLF-intensity functions represent asymptotic values obtained at high SLs. These asymptotic DLFs were abnormal in the majority of hearing-impaired subjects, with more than half the data in excess of two standard deviations above normal. However, among those subjects, the correlation between the DLF deficit and the amount of hearing loss at the test frequency was not strong (
r
=+.27).
Enhancement of Word-Recognition Performance With a Filtering Technique
Authors: Wilson Richard H. , Preece John P. , Crowther Courtney S.
Published: July 2014

The NU No. 6 materials spoken by a female speaker were passed through a notch filter centered at 247 Hz with a 34-dB depth The filtering reduced the amplitude range within the spectrum of the materials by 10 dB that was reflected as a 7.5-vu reduction measured on a true vu meter. Thus, the notch filtering in effect changed the level calibration of the materials. Psychometric functions of the NU No. 6 materials filtered and unfiltered in 60-dB SPL broadband noise were obtained from 12 listeners with normal hearing. Although the slopes of the functions for the two conditions were the same, the functions were displaced by an average of 5 8 dB with the function for the filtered materials located at the lower sound-pressure levels.
Comprehension Problems in Children With Specific Language Impairment
Authors: Bishop D. V. M. , Adams C.
Published: July 2014

A group of 61 schoolchildren with specific language impairment (SLI) was compared with a control group on a comprehension task, in which the child was questioned about a story that had been presented either orally or as a series of pictures. Half the questions were literal, requiring the child to provide a detail that had been mentioned or shown explicitly in the story. The remainder required the child to make an inference about what had not been directly shown or stated. SLI children were impaired on this task, even after taking into account "comprehension age," as assessed on a multiple-choice test. However, the effects of mode of presentation and question type were similar for control and SLI groups. Children who fitted the clinical picture of semantic-pragmatic disorder had lower scores than other SLI children on this task. In addition, they were more prone to give answers that suggested they had not understood the question. However, as with the other SLI children, there was no indication that they had disproportionate difficulty with inferential questions. It is concluded that SLI children are impaired in constructing an integrated representation from a sequence of propositions, even when such propositions are presented nonverbally.
Vocal Tract Area Function Estimation From Midsagittal Dimensions With CT Scans and a Vocal Tract Cast
Authors: Perrier Pascal , Boë Louis-Jean , Sock Rudolph
Published: July 2014

The generation of area functions from measurements of the sagittal section is an important step in the study of the relation between vocal tract geometry and speech acoustics. We present a new model to perform this transformation, inspired by the αβ model of Heinz & Stevens (1965). Our model is based on analysis of a vocal tract cast for large sagittal dimensions and for small sagittal dimensions on CT scans of the vocal tract constriction zones for the three cardinal vowels [i, a, u] of French. We extracted two sets of coefficients, appropriate for large and small sagittal dimensions respectively. We then compared the predictions of the model with those of other models from the literature. Finally, the usefulness of this dual coefficient procedure for the acoustic simulation of vowels was tested using sagittal sections generated by an acoustic model of the vocal tract.
Phonological Behavior in Toddlers With Slow Expressive Language Development
Authors: Paul Rhea , Jennings Patricia
Published: July 2014

Toddlers with slow expressive language development were compared to normally speaking age-mates on three global measures of phonological behavior: the average level of complexity of their syllable structures, the number of different consonant phonemes produced, and the percentage of consonants correctly produced in intelligible utterances. The groups were found to differ significantly on all three variables. Further analyses were done, breaking the groups down into narrower age ranges. These comparisons also revealed differences between late-talking and normal youngsters. Detailed analyses of the range of phonemes and syllable structures produced, as well as the appearance of phoneme classes within syllable structures and positions, revealed that late talkers showed a delayed rather than a deviant pattern of phonological development. The implications of these findings for identifying and monitoring expressive delay in toddlers are discussed.
Acoustic-Phonetic Contrasts and Intelligibility in the Dysarthria Associated With Mixed Cerebral Palsy
Authors: Ansel Beth M. , Kent Raymond D.
Published: July 2014

This study evaluated the relationship between specific acoustic features of speech and perceptual judgments of word intelligibility of adults with cerebral palsy-dysarthria. Use of a contrasting word task allowed for intelligibility analysis and correlated acoustic analysis according to specified spectral and temporal features. Selected phonemic contrasts included syllable-initial voicing; syllable-final voicing; stop-nasal; fricative-affricate; front-back, high-low, and tense-lax vowels. Speech materials included a set of CVC stimulus words.

Acoustic data are reported on vowel duration, formant frequency locations, voice onset times, amplitude rise times, and frication durations. Listeners’ perceptual assessment of intelligibility of the 16 dysarthric adults by transcription and rating tasks is also presented. All but one acoustic contrast was successfully made as evidenced by measured acoustic differences between contrast pairs. However, the generally successful acoustic contrasts stood in marked contrast to the poorly rated intelligibility scores and high error percentages that were ascribed to the opposite pair members.

A second analysis examined the contribution of these acoustic features towards estimates and prediction of intelligibility deficits in speakers with dysarthria. The scaled intelligibility was predicted by multiple regression analysis with 62.6% accuracy by acoustic measures related to one consonant contrast (fricative-affricate) and three vowel contrasts (front-back, high-low, and tense-lax). Other measured contrasts, such as those related to contrast voicing effects and stop-nasal distinctions, did not seem to contribute in a significant way to variability in the intelligibility estimates. These findings are discussed in relation to specific areas of production deficiency that are consistent across different types of dysarthria with cerebral palsy as the etiology.
Individualized Correction Factors in the Preselection of Hearing Aids
Authors: Fikret-Pasa Selda , Revit Lawrence J.
Published: July 2014

This study investigated three issues involving corrections for individual ear acoustics in hearing aid prescriptions: (a) the extent to which inconsistencies in the sound-field reference position can affect comparative corrections for the real-ear unaided response (REUR); (b) the extent to which individual variability in the real-ear-to-coupler level difference (RECD) supports the use of individual measurements as opposed to an average-ear estimate; and (c) the adequacy of using KEMAR estimates of the effects of the location of the hearing aid microphone. In Experiment 1, KEMAR REURs using over-the-ear and under-the-ear reference positions were compared with KEMAR REURs using a center-of-head reference position. Maximum differences of 4–9 dB were found in the 1500- to 5000-Hz range, depending on test conditions. In Experiment 2, the ear canal response of an insert earphone was compared to the 2-cc coupler response of the same earphone to calculate the RECD. Individual RECDs for a population of hearing aid candidates were compared to the RECD for KEMAR. For 8 of the 15 subjects (9 of 18 ears), the RECD was more than 4 dB different from KEMAR at two or more third-octave frequencies between 500 and 4000 Hz. In Experiment 3, the effect of the location of the hearing aid microphone for in-the-ear (ITE) and in-the-canal (ITC) locations was compared with the over-the-ear (OTE) location for 18 ears and for KEMAR. The effects varied across individual ears, but all ears and KEMAR showed positive gain in the high frequencies for the ITE and ITC locations. The relevance of these results to hearing aid prescription practices is discussed.
Temporal Resolution in Normal-Hearing and Hearing-Impaired Listeners Using Frequency-Modulated Stimuli
Authors: Madden John P. , Feth Lawrence L.
Published: July 2014

This study compares the temporal resolution of frequency-modulated sinusoids by normal-hearing and hearing-impaired subjects in a discrimination task. One signal increased linearly by 200 Hz in 50 msec. The other was identical except that its trajectory followed a series of discrete steps. Center frequencies were 500, 1000, 2000, and 4000 Hz. As the number of steps was increased, the duration of the individual steps decreased, and the subjects’ discrimination performance monotonically decreased to chance. It was hypothesized that the listeners could not temporally resolve the trajectory of the step signals at short step durations. At equal sensation levels, and at equal sound pressure levels, temporal resolution was significantly reduced for the impaired subjects. The difference between groups was smaller in the equal sound pressure level condition. Performance was much poorer at 4000 Hz than at the other test frequencies in all conditions because of poorer frequency discrimination at that frequency.
Laryngeal Paralyses
Authors: Smith Marshall E. , Berke Gerald S. , Gerratt Bruce R. , Kreiman Jody
Published: July 2014

The neurological causes of vocal fold paralyses have been well documented. However, the effect of these disorders on laryngeal vibration is not well understood. A theoretical four-mass model of the larynx, based on the work of Ishizaka and Isshiki (1976) and Koizumi, Taniguchi, and Hiromitsu (1987), was developed and adapted to simulate laryngeal biomechanical behavior. The model was used to evaluate various states of asymmetric laryngeal vibration. Input parameters that relate observed laryngeal function and model simulation were developed. Laryngeal paralyses were simulated by their predicted effect on these parameters. Simulations were compared with available data on glottal vibration in laryngeal paralyses. Complex modes of vibration were seen with certain combinations of asymmetrical lower mass stiffness and initial glottal gap.
The Acquisition of Unrounded Vowels in English
Authors: Otomo Kiyoshi , Stoel-Gammon Carol
Published: July 2014

This study investigated developmental patterns of acquisition of the unrounded American English vowels /i,
i
, e, ε, æ, α/ by following 6 normally developing children from 22 to 30 months of age. The subjects were examined at approximately 22, 26, and 30 months of age. Results showed that, in general, /1/ and /α/ were mastered early and /
i
/ and /ε/ were least accurate throughout the period of the study. Upon inspection of errors, the following three classes of production errors were identified (a) intertrial production variability, (b) context-sensitive substitutions, and (c) context-free systematic substitution patterns, or articulatory processes. A decrease in production variability and in the occurrence of articulatory processes with age generally coincided with a gradual mprovement in accuracy of production. However, substitutions of lower vowels for /
i
/ were persistent, and the pattern was observed even at 30 months of age. Individual variation was also evident in the production accuracy, the substitution patterns, and the manner of articulatory improvement
Modulation Detection in Subjects With Relatively Flat Hearing Losses
Authors: Bacon Sid P. , Gleitman Ronald M.
Published: July 2014

Modulation detection thresholds were measured as a function of modulation frequency in 5 normal-hearing subjects and in 8 subjects with relatively flat, slight-to-moderate hearing losses. The carrier was a broadband noise that was sinusoidally amplitude modulated (SAM) in one of two observation intervals The spectrum level of the carrier ranged from –10 to 50 dB SPL, and, for a given carrier level, modulation frequency varied from 2 to 1024 Hz. The temporal modulation transfer functions (TMTFs) were fitted very well with a simple equation describing a low-pass filter function The TMTFs from the normal-hearing subjects were relatively independent of carrier level, although the derived time constant tended to increase slightly with decreases n carrier level, from an average value of 2.5 msec at 30 dB SPL to 6.0 msec at –10 dB SPL. In addition, sensitivity to amplitude modulation (AM) decreased by about 4 dB as the pressure spectrum level of the carrier was decreased from 0 to –10 dB SPL. The TMTFs from 7 of the 8 hearing-impaired subjects were similar to those from the normal-hearing subjects when the carriers were presented at equal SPLs, except that the derived time constants were slightly larger in the subjects with hearing impairment When comparisons were made at comparable sensation levels (SLs), however, the TMTFs from the two groups of subjects were quantitatively similar, with the exception that at the lowest SL (20 dB), hearing-impaired subjects typically were
more sensitive
to AM than normal-hearing subjects, and the derived time constants from their TMTFs were somewhat
smaller
These results, taken together with previously published results, suggest that a broad listening bandwidth is important for normal performance on a temporal resolution task. That the time constant from one of the hearing-impaired subjects was significantly longer than normal, regardless of whether the comparisons were made at equal SPL or equal SL, indicates that other factors can also be important
Reliability of Two Measures of Speech Recognition in Elderly People
Authors: Cokely Carol Geltman , Humes Larry E.
Published: July 2014

The revised Speech Perception in Noise (SPIN) test and the Dichotic Sentence Identification (DSI) test have been used to help evaluate speech-recognition capabilities in elderly people. We evaluated the test-retest reliability of these measures for 17 subjects aged 63–82 years. The DSI and revised SPIN tests were administered at 65, 75, and 85 dB SPL, with a total of three presentations at each level. Reliability was assessed using a repeated-measures analysis of variance and 95% critical differences for each test. Results raise serious questions about the use of these tests for diagnostic determinations or assessment of speech-recognition ability in elderly people
Form Equivalence of the Selective Auditory Attention Test Administered to 6-Year-Old Children
Authors: Chermak Gail D. , Montgomery M. Janet
Published: July 2014

The form equivalence of the Selective Auditory Attention Test (SAAT) was examined. Forty normal-hearing 6-year-old boys and girls were assigned randomly in equal numbers to one of two groups. Each group listened to four lists of words at 70 dB SPL sound field in one of two orders. Equal mean difficulty and significant correlations between lists in quiet and between lists presented with competing speech substantiate the form equivalence of the SAAT. Form equivalence analyzed for individual subjects confirmed conclusions derived from analysis of group data. A learning effect seen as improved mean performance for the second of the two lists resented in competing speech resulted from the repeated measures experimental design of the study and does not undermine the clinical viability of the SAAT.
Parent Verbal Interactions and Speech Rate
Authors: Guitar Barry , Schaefer Helen Kopff , Donahue-Kilburg Gail , Bond Lynne
Published: July 2014

This single-case study of indirect stuttering treatment is intended to identify variables for further research. The study used post hoc analyses of changes in parent speech variables and changes in the child’s stuttering. The analysis was conducted in two parts. Study I examined the relationships between the child’s percent syllables stuttered and the parents’ speech rates and percentages of nonaccepting statements, interruptions, questions, nonaccepting questions, and talk time. The only parent variable significantly correlated with the child’s stuttering was the mother’s speech rate. In Study II the child’s percent syllables stuttered were subdivided into primary (effortless) and secondary (tense) stuttering. Each category was then correlated with the parent variables examined previously. Results suggested that the parent variables that were significantly related to the child’s primary stuttering were not the same as those significantly related to her secondary stuttering. Specific parent variables are suggested for further study.
Specific-Language-Impaired Children’s Quick Incidental Learning of Words
Authors: Rice Mabel L. , Buhr JoAnn , Oetting Janna B.
Published: July 2014

It was hypothesized that the initial word comprehension of specific-language-impaired children would be enhanced by the insertion of a short pause just before a sentence-final novel word. Three groups of children served as subjects: twenty 5-year-old, specific-languageimpaired (SLI) children, and two comparison groups of normally developing children, 20 matched for mean length of utterance (MLU) and 32 matched for chronological age (CA). The children were randomly assigned to two conditions for viewing video programs. The programs were animated stories that featured five novel object words and five novel attribute words, presented in a voice-over narration. The experimental version introduced a pause before the targeted words; the control version was identical except for normal prosody instead of a pause. Counter to the predictions, there was no effect for condition. Insertion of a pause did not improve the SLI children’s initial comprehension of novel words. There were group main effects, with the CA matches better than either of the other two groups and no differences between the SLI children and the MLU-matched children.
Grammatical Morphology and Speech Perception in Children With Specific Language Impairment
Authors: Leonard Laurence B. , McGregor Karla K. , Allen George D.
Published: July 2014

Many English-speaking children with specific language impairment have been found to be especially weak in their use of grammatical morphology. In a separate literature, many children meeting the same subject description have shown significant limitations on tasks involving the perception of rapid acoustic changes. In this study, we attempted to determine whether there were parallels between the grammatical morphological limitations of children with specific language impairment and their performance profiles across several perceptual contrasts. Because most English grammatical morphemes have shorter durations relative to adjacent morphemes in the speech stream, we hypothesized that children with specific language impairment would be especially weak in discriminating speech stimuli whose contrastive portions had shorter durations than the noncontrastive portions. Results from a group of eight children with specific language impairment with documented morphological difficulties confirmed these predictions. Several possible accounts of the observed morphology-perception parallels are offered.