Peak clipping is a common form of distortion in hearing aids and can reduce the subjective quality of the amplified speech. In a previous study involving listeners with normal hearing (Kates & Kozma-Spytek, 1994), the effect of peak clipping on speech quality ratings was studied using sentence test materials that were filtered using three different frequency response contours and then clipped at four different clipping levels. The present study extends the quality ratings to include those from a group of listeners having moderate to profound hearing impairments. The experimental results indicate that the clipping level, and the interaction of the frequency-response shaping with the clipping level, significantly affects speech quality. It is also shown that the distortion effects on speech quality for the listeners with impaired hearing can be modeled by a distortion index computed from the magnitude-squared coherence of the speech-processing system in response to a shaped-noise input signal. The distortion-index weights derived for the group of listeners with impaired hearing, however, differ substantially from those derived for listeners with normal hearing, and substantial inter-listener variation was also observed.
Ninety-six adults with normal hearing viewed three types of recorded speechreading materials (consonant-vowel nonsense syllables, isolated words, and sentences) on 2 days. Responses to nonsense syllables were scored for syllables correct and syllable groups correct; responses to words and sentences were scored in terms of words correct, phonemes correct, and an estimate of visual distance between the stimulus and the response. Generalizability analysis was used to quantify sources of variability in performance. Subjects and test items were important sources of variability for all three types of materials; effects of talker and day of testing varied but were comparatively small. For each type of material, alternative models of test construction and test-score interpretation were evaluated through estimation of generalizability coefficients as a function of test length. Performance on nonsense syllables correlated about .50 with both word and sentence measures, whereas correlations between words and sentences typically exceeded .80.
To further investigate the effects that argument structure can have on language processing, reaction-time (RT) and event-related potential (ERP) data were collected for 14 younger subjects (M = 23 years) and 13 older subjects (M = 66 years). A cross-modal lexical decision (CMLD) task, involving online processing of high- and low-complexity verbs embedded in sentences, was used. Results of a baseline nonlinguistic visual ERP task indicated that the older group of subjects demonstrated significantly longer P300 latencies and significantly lower P300 amplitudes than the younger subjects. In the sentence task, younger subjects exhibited significantly higher P300 amplitudes when processing high- versus low-complexity verbs, with a similar pattern noted for the older subjects. P300 latencies were significantly shorter for the older group than the younger group. Neither P300 latencies nor RTs were significantly related to verb complexity, although medium to large effect sizes were present. Overall, these findings support earlier notions of argument structure effects.
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.
Children with slow expressive language development (SELD) as toddlers and a control group of children with normal language development (NL) were followed to early school age. Children with SELD were, at that point, subdivided into two groups: those who had moved within the normal range of expressive language (the History of Expressive Language Delay [HELD] subgroup); and those who continued to score below the normal range in expressive language at school age (the Expressive Language Delay [ELD] subgroup). During their kindergarten, first, and second grade years, they were administered a narrative generation task. Narratives were analyzed for MLU, lexical diversity, amount of information included, proportion of complete cohesive ties, and overall stage of narrative maturity. In kindergarten, children with normal language history scored significantly higher than those with HELD and ELD on lexical diversity and narrative stage; and higher than those with ELD in proportion of complete cohesive ties. In first grade, children with normal language history again scored significantly higher than those with HELD and ELD on narrative maturity, with no other significant differences. In second grade, there were no significant differences among the groups.
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.
The Developmental Weighting Shift (DWS) suggests that children adjust the weights they assign to the acoustic parameters of the speech signal as they gain experience with a native language, and that this developmental shift in perceptual weighting strategies is related to another developmental change: increased sensitivity to the phonetic structure of the speech signal. To test these claims, children presumed to differ in the amount of linguistic experience they had received during their preschool years participated in two kinds of tasks: a labeling task designed to estimate differences among groups in the weights assigned to various acoustic parameters, and tasks of phonemic awareness. The experimental groups were children from low-socioeconomic (low-SES) backgrounds, children with histories of chronic otitis media (OM), and children who experienced both conditions. A control group of children who experienced neither of these conditions also participated. The hypotheses were that, because of their diminished linguistic experience, children in the three experimental groups would display both more immature weighting strategies and poorer phonemic awareness than children in the control group, and that developmental advance in perceptual weighting strategies and phonemic awareness would be correlated. Results indicated that children with histories of chronic OM performed more poorly on both kinds of tasks than did children in the control group, and low-SES children performed more poorly still. Children experiencing both low-SES and chronic OM performed no differently than the low-SES children. These results provide support for the claim that the development of mature perceptual weighting strategies for speech and of phonemic awareness are related. Support is also provided for the claim that both depend on receiving sufficient and appropriate experience with a native language during the preschool years.
Glottal stops that occur in vowel-consonant-vowel context are often not realized as stops at all, but rather show voicing that is continuous throughout the glottal constriction gesture. Glottal articulations that are realized in this way are apparently marked by reductions in amplitude and fundamental frequency. In the present study measurements from naturally produced utterances containing the sequence /o?o/ (i.e., a glottal stop separating two identical vowels) were used to create a set of synthetic stimuli that varied in their F0 and amplitude contours. The utterances were resynthesized in six ways: (a) original pitch/original amplitude, (b) original pitch/flat amplitude, (c) flat pitch/original amplitude, (d) flat pitch/flat amplitude, (e) flat pitch/inverted amplitude, and (f) inverted pitch/flat amplitude. Results indicated that: (a) a dip in the pitch contour is nearly always sufficient to cue the presence of a glottal stop in the absence of any drop in amplitude, (b) a dip in the amplitude contour is usually sufficient to cue the presence of a glottal stop, and (c) signals with inverted contours were not heard as glottal stops, indicating that it is not merely an abrupt change that is needed to signal a glottal stop.
The dysarthrias form a group of diverse, chronic motor speech disorders. The disorders of Parkinsan's disease; stroke, traumatic brain injury, amyotrophic lateral sclerosis, and cerebral palsy are reviewed because they represent important clinical diagnoses in which dysarthria is a frequent and debilitating symptom. The roles played by speech-language pathologists include participation in differential diagnosis, provision of speech treatment, staging of treatment, and timely education so that clients and families can make informed decisions about communication alternatives. Both scientific and clinical evidence is presented that suggests that individuals with dysarthria benefit from the services of speech-language pathologists. Group-treatment studies, single-subject studies, and case reports illustrate the effectiveness of various types of speech treatment. Research into the effectiveness of augmentative and alternative communication systems for individuals with cerebral palsy is also presented.
Traumatic brain injuries (TBI) may result in a broad array of cognitive-communicative impairments. Cognitive-communicative impairments are the result of deficits in linguistic and nonlinguistic cognitive functions. The speech-language pathologist functions as a member of the multidisciplinary team of professionals that collaboratively assess and treat individuals with TBI. The role of the speech-language pathologist includes assessment of all aspects of communication, as well as the communicative implications of cognitive deficits, and swallowing; treatment planning and programming, as determined by the individual's stage of recovery; client and family training/counseling; and interdisciplinary consultation. The effectiveness of speech and language intervention for specific cognitive deficits (e.g., attention, memory, executive functions) as well as general issues of social-skills training and early intervention are illustrated by scientific and clinical evidence from group-treatment and single-subject studies as well as case studies.
No AccessJournal of Speech, Language, and Hearing ResearchLetter to the Editor1 Feb 1996A Potential Limitation of Treatment Efficacy Research: A Comment on Camarata, Nelson, and Camarata (1994) David Snow, Linda Swisher, Mary McNamara, and Barbara Kiernan David Snow Child Language Center The University of Arizona Tucson, AZ 85721 Google Scholar More articles by this author , Linda Swisher Child Language Center The University of Arizona Tucson, AZ 85721 Google Scholar More articles by this author , Mary McNamara Child Language Center The University of Arizona Tucson, AZ 85721 Google Scholar More articles by this author and Barbara Kiernan Child Language Center The University of Arizona Tucson, AZ 85721 Google Scholar More articles by this author https://doi.org/10.1044/jshr.3901.221 SectionsAboutFull TextPDF ToolsAdd to favoritesDownload CitationTrack Citations ShareFacebookTwitterLinked In References Camarata, S. M., Nelson, K. E., & Camarata, M. N. (1994). Comparison of conversational-recasting and imitative procedures for training grammatical structures in children with specific language language impairment.Journal of Speech and Hearing Research, 37, 1414–1423. ASHAWireGoogle Scholar Connell, P. J., & Stone, C. A. (1992). Morpheme learning of children with specific language impairment under controlled instructional conditions.Journal of Speech and Hearing Research, 35, 844–852. ASHAWireGoogle Scholar Additional Resources FiguresReferencesRelatedDetailsCited by Journal of Positive Behavior Interventions5:3 (171-178)1 Jul 2003A Comparison of Naturalistic and Analog Treatment Effects in Children with Expressive Language Disorder and Poor Preintervention Imitation SkillsHeather Gillum, Stephen Camarata, Keith E. Nelson and Mary N. Camarata Journal of Speech, Language, and Hearing Research40:1 (5-19)1 Feb 1997Two Models of Grammar Facilitation in Children With Language ImpairmentsMarc E. Fey, Patricia L. Cleave and Steven H. LongJournal of Speech, Language, and Hearing Research39:1 (222-223)1 Feb 1996On the Importance of Procedural Descriptions in Treatment Efficacy Research: A Response to Snow, Swisher, McNamara, and Kiernan (1996)Stephen Camarata, Keith E. Nelson and Mary Camarata Volume 39Issue 1February 1996Pages: 221-222 Get Permissions Add to your Mendeley library HistoryReceived: May 8, 1995Accepted: Aug 4, 1995 Published in issue: Feb 1, 1996 Metrics Topicsasha-topicsasha-article-typesCopyright & PermissionsCopyright © 1996 American Speech-Language-Hearing AssociationPDF downloadLoading ...
This study reports changes in acoustic, respiratory, laryngeal, and articulatory kinematics of 3 males who stutter, following participation in a version of the Hollins Precision Fluency Shaping Program. Two nonstuttering controls received no treatment. Subjects repeated phrases of the form "He see CVC again" at self-selected slow, normal, and fast speaking rates. For experimental subjects, acoustic duration of the phrases increased significantly in 7 out of 9 comparisons of before- and after-treatment conditions, whereas controls decreased the duration of the phrases in 4 out of 6 comparisons of measurements made over approximately the time interval during which the experimental group received treatment. The experimental group increased inspiratory volume for 7 out of 9 conditions and average expiratory flow significantly for all conditions, whereas the controls decreased both. The experimental group prolonged laryngeal opening in 6 of 7 comparisons, but only 3 of the increases were significant. Lip and jaw movements for consonants were significantly reduced in amplitude for the experimental group for 30 of 36 measures. The direction of change for laryngeal and upper articulator measures was mixed for controls. These results show that behavioral treatment can produce significant changes in the fluent speech of persons who stutter with respect to respiration, laryngeal valving, and articulation. Possible relationships between the observed changes in speech production and the increased fluency of the subjects are discussed.
To examine the role of different cognitive processes in accounting for the slower naming times of children with specific language impairment (SLI) relative to peers with no language impairment (NLI), three tasks designed to stress different types of processing, were administered: naming pictures with the signal to respond presented at various delay intervals, naming following different durations of exposure to identical and unrelated primes, and vocally responding to nonlinguistic stimuli. Children with SLI, aged 4 to 9.5 years, were significantly slower than their NLI age peers on naming and on responding to nonlinguistic stimuli, but the effect of delay interval before naming and of duration of prime exposure before naming was similar for both groups. Results suggested that speed of naming is related to the slower nonlinguistic response processing of children with SLI and not to speed of their linguistic or perceptual processing. To examine differences in processing that might relate to pattern of language performance we examined responses of two subgroups of SLI. The subgroup of children whose language problems involved expressive but not receptive skills was not significantly slower than their NLI peers. The children whose problems involved both expressive and receptive language were significantly slower, but this was influenced by age. Findings are discussed in terms of language performance, age, task variables, and a generalized rate-limiting factor.
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 lambda 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 intraarticulator 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.
In an earlier study, we evaluated the effectiveness of several acoustic measures in predicting breathiness ratings for sustained vowels spoken by nonpathological talkers who were asked to produce nonbreathy, moderately breathy, and very breathy phonation (Hillenbrand, Cleveland, & Erickson, 1994). The purpose of the present study was to extend these results to speakers with laryngeal pathologies and to conduct tests using connected speech in addition to sustained vowels. Breathiness ratings were obtained from a sustained vowel and a 12-word sentence spoken by 20 pathological and 5 nonpathological talkers. Acoustic measures were made of (a) signal periodicity, (b) first harmonic amplitude, and (c) spectral tilt. For the sustained vowels, a frequency domain measure of periodicity provided the most accurate predictions of perceived breathiness, accounting for 92% of the variance in breathiness ratings. The relative amplitude of the first harmonic and two measures of spectral tilt correlated moderately with breathiness ratings. For the sentences, both signal periodicity and spectral tilt provided accurate predictions of breathiness ratings, accounting for 70%-85% of the variance.
This paper presents the results of a controlled trial of child stuttering treatment. The aim of the study was, first, to compare the effectiveness of three viable treatments, and, second, to compare these three treatments to a no-treatment control composed of children who stuttered of a similar age and sex ratio who were on treatment waiting lists. The three treatments investigated included intensive smooth speech, intensive electromyography feedback, and home-based smooth speech. The children/adolescents were assessed across three speaking contexts on measures of percentage syllables stuttered (%SS) and syllables spoken per minute (SPM) and outcomes were assessed 12 months later. Repeated measures analyses of variance demonstrated significant differences between the control group and all three treatment groups across time on conversations in;the clinic, on the telephone, and at home (although home measures were not taken for the intensive smooth speech group). Although the controls' stuttering did not change across time, the treatment groups' stuttering was decreased to very low levels posttreatment (less than 1% syllables stuttered on average), with mean improvement in stuttering frequency of at least 85% to 90% across all assessment contexts. Stuttering did not increase significantly up to 3 months and one year posttreatment in the experimental groups, although levels did rise across time (less than 3% syllables stuttered on average). Speech naturalness results showed increasing naturalness across time as rated by the clinician and parent. This was not the case for the controls. The children were also less anxious across time following treatment. The results suggest that all three treatments for children aged 9-14 who stutter were very successful in the long term for over 70% of the group, though the EMG feedback and home-based treatments were superior when percentages falling below a cutoff point (2%SS) were used to discriminate between groups. Implications for child/adolescent treatment in the community are discussed. Long-term outcomes will be assessed up to 5 years after the treatment.
Twenty children who have worn a Cochlear Corporation cochlear implant for an average of 33.6 months participated in a device-on/off experiment. They spoke 14 monosyllabic words three times each after having not worn their cochlear implant speech processors for several hours. They then spoke the same speech sample again with their cochlear implants turned on. The utterances were phonetically transcribed by speech-language pathologists. On average, no difference between speaking conditions on indices of vowel height, vowel place, initial consonant place, initial consonant voicing, or final consonant voicing was found. Comparisons based on a narrow transcription of the speech samples revealed no difference between the two speaking conditions. Children who were more intelligible were no more likely to show a degradation in their speech production in the device-off condition than children who were less intelligible. In the device-on condition, children sometimes nasalized their vowels and inappropriately aspirated their consonants. Their tendency to nasalize vowels and aspirate initial consonants might reflect an attempt to increase proprioceptive feedback, which would provide them with a greater awareness of their speaking behavior.
A two-part study was conducted to determine the sources of variation in nasalance scores derived from the Nasometer. In Study #1, a function generator was used as a signal source to calibrate and input sine and square waves directly into the Nasometer. Ten stimuli ranging from 105 to 330 Hz in 25 Hz increments were evaluated. In Study #2, the same signal source and an amplified loudspeaker were used to calibrate and present square waves to the nasometer via five different sets of microphones. The sound pressure level of all stimuli was maintained at 88 dB. Each microphone set was calibrated using the 105 Hz signals. Results from Study #1 indicated consistent nasalance scores across all frequencies (i.e., all scores were within 2% of calibration). Results from Study #2 demonstrated deviations greater than 2% from calibration as a function of frequency for all five sets of microphones. The smallest deviation was 5%, whereas the largest deviation was 14%. We suggest that the variation in nasalance as a function of stimulus frequency may be due to a mismatch in the sensitivity of microphones (i.e., different frequency response characteristics). It is further suggested (a) that individual investigators determine the response characteristics of their microphones and (b) that relatively small variations in nasalance scores (i.e., 5-14%) either within or across speakers be interpreted with caution.
The present study investigated whether children with specific language impairment (SLI) differed from children with normal language learning in their ability to process binaural temporal information. The SLI group was matched with peers of the same chronological age, as well as peers with similar language age. All three subject groups were tested with measures of complex sound localization involving the precedence effect phenomenon. Subjects were required to track the apparent motion of a “moving” fused auditory image (FAI). Movement of the FAI was simulated by varying the delay incrementally between pairs of clicks presented, one each, from two matched loudspeakers placed on opposite sides of the child’s head. With this task, the SLI subjects’ performances were found to be similar to their language age-matched but chronologically younger peers. Both groups exhibited tracking skills that were statistically poorer than that of the chronologically age-matched group. Additional tests indicated this effect was not due to differences in motoric tracking abilities nor to the SLI subjects’ abilities to perceive small binaural time cues. Thus, children with SLI appear to be impaired in their ability to use binaural acoustic information in a dynamic ongoing fashion. The requirements for processing such nonlinguistic acoustic information in a “dynamic and ongoing” fashion may be similar to those involved in the ongoing processing of rapid changes in the temporal and spectral components of the speech chain.
Spontaneous language samples of 30 24-month-old toddlers diagnosed with Specific Expressive Language Impairment (SLI-E) were compared with samples produced by an age-matched group of 30 typically developing toddlers. Vocalization patterns, phonetic inventories, and syllable formation patterns were compared. Toddlers with SLI-E vocalized significantly less often than their typically developing peers, had proportionately smaller consonantal and vowel inventories, and used a more restricted and less mature array of syllable shapes. Although the mean incidence of phoneme usage varied significantly in all comparisons, profiles of consonant usage were similar between the two groups for initial phoneme usage, but considerably different for final consonant closure. Such patterns of vocal and phonetic behavior confirm earlier reports of phonetic delay in SLI-E, and suggest that nongrammatical factors contribute to the development of expressive language deficits in toddlers. We further propose a bidirectional model for the expressive deficits in SLI-E, in which the child’s limited phonetic capacity interacts with propensities in caretaker interaction to further reduce opportunities for expressive language learning and practice.
