The purpose of this study was to assess the time course of spoken word recognition in 2-year-old children who use cochlear implants (CIs) in quiet and in the presence of speech competitors.
Children who use CIs and age-matched peers with normal acoustic hearing listened to familiar auditory labels, in quiet or in the presence of speech competitors, while their eye movements to target objects were digitally recorded. Word recognition performance was quantified by measuring each child's reaction time (i.e., the latency between the spoken auditory label and the first look at the target object) and accuracy (i.e., the amount of time that children looked at target objects within 367 ms to 2,000 ms after the label onset).
Children with CIs were less accurate and took longer to fixate target objects than did age-matched children without hearing loss. Both groups of children showed reduced performance in the presence of the speech competitors, although many children continued to recognize labels at above-chance levels.
The results suggest that the unique auditory experience of young CI users slows the time course of spoken word recognition abilities. In addition, real-world listening environments may slow language processing in young language learners, regardless of their hearing status.
Understanding the long-term outcomes of developmental language difficulties is key to knowing what significance to attach to them. To date, most prognostic studies have tended to be clinical rather than population-based, which necessarily affects the interpretation. This study sought to address this issue using data from a U.K. birth cohort of 17,196 children, following them from school entry to adulthood, examining literacy, mental health, and employment at 34 years of age. The study compared groups with specific language impairment (SLI), nonspecific language impairment (N-SLI), and typically developing language (TL).
Secondary data analysis of the imputed 5-year and 34-year data was carried using multivariate logistic regressions.
The results show strong associations for demographic and biological risk for both impairment groups. The associations are consistent for the N-SLI group but rather more mixed for the SLI group.
The data indicate that both SLI and N-SLI represent significant risk factors for all the outcomes identified. There is a strong case for the identification of these children and the development of appropriate interventions. The results are discussed in terms of the measures used and the implications for practice.
Clinical grammar markers are needed for children with SLI older than 8 years. This study followed children who were previously studied on sentences with omitted finiteness to determine if affected children continue to perform at low levels and to examine possible predictors of low performance. This is the first longitudinal report of grammaticality judgments of questions.
Three groups of children participated: 20 SLI, 20 age controls, and 18 language-matched controls, followed from ages 6–15 years. An experimental grammaticality judgment task was administered with BE copula/auxiliary and DO auxiliary in wh- and yes/no questions for 9 times of measurement. Predictors were indices of vocabulary, nonverbal intelligence, and maternal education.
Growth curve analyses show that the affected group performed below the younger controls at each time of measurement, for each variable. Growth analyses show linear and quadratic effects for both groups across variables, with the exception of BE acquisition, which was flat for both groups. The control children reached ceiling levels; the affected children reached a lower asymptote.
The results suggest an ongoing maturational lag in finiteness marking for affected children with promise as a clinical marker for language impairment in school-aged and adolescent children and probably adults as well.
To examine when and how socially conditioned distinct speaking styles emerge in typically developing preschool children's speech.
Thirty preschool children, ages 3, 4, and 5 years old, produced target monosyllabic words with monophthongal vowels in different social–functional contexts designed to elicit clear and casual speaking styles. Thirty adult listeners were used to assess whether and at what age style differences were perceptible. Children's speech was acoustically analyzed to evaluate how style-dependent differences were produced.
The ratings indicated that listeners could not discern style differences in 3-year-olds' speech but could hear distinct styles in 4-year-olds' and especially in 5-year-olds' speech. The acoustic measurements were consistent with these results: Style-dependent differences in 4- and 5-year-olds' words included shorter vowel durations and lower fundamental frequency in clear compared with casual speech words. Five-year-olds' clear speech words also had more final stop releases and initial sibilants with higher spectral energy than did their casual speech words. Formant frequency measures showed no style-dependent differences in vowel production at any age nor any differences in initial stop voice onset times.
Overall, the findings suggest that distinct styles develop slowly and that early style-dependent differences in children's speech are unlike those observed in adult clear and casual speech. Children may not develop adultlike styles until they have acquired expert articulatory control and the ability to highlight the internal structure of an articulatory plan for a listener.
The question of how and when English-speaking children acquire auxiliaries is the subject of extensive debate. Some researchers posit the existence of innately given Universal Grammar principles to guide acquisition, although some aspects of the auxiliary system must be learned from the input. Others suggest that auxiliaries can be learned without Universal Grammar, citing evidence of piecemeal learning in their support. This study represents a unique attempt to trace the development of auxiliary syntax by using a longitudinal elicitation methodology.
Twelve English-speaking children participated in 3 tasks designed to elicit auxiliary BE in declaratives and yes/no and wh-questions. They completed each task 6 times in total between the ages of 2;10 (years;months) and 3;6.
The children's levels of correct use of 2 forms of BE (is, are) differed according to auxiliary form and sentence structure, and these relations changed over development. An analysis of the children's errors also revealed complex interactions between these factors.
These data are problematic for existing accounts of auxiliary acquisition and highlight the need for researchers working within both generativist and constructivist frameworks to develop more detailed theories of acquisition that directly predict the pattern of acquisition observed.
The study of auxiliary acquisition is central to work on language development and has attracted theoretical work from both nativist and constructivist approaches. This study is part of a 2-part companion set that represents a unique attempt to trace the development of auxiliary syntax by using a longitudinal elicitation methodology. The aim of the research described in this part is to track the development of modal auxiliaries and auxiliary DO in questions and declaratives to provide a more complete picture of the development of the auxiliary system in English-speaking children.
Twelve English-speaking children participated in 2 tasks designed to elicit auxiliaries CAN, WILL, and DOES in declaratives and yes/no questions. They completed each task 6 times in total between the ages of 2;10 (years;months) and 3;6.
The children's levels of correct use of the target auxiliaries differed in complex ways according to auxiliary, polarity, and sentence structure, and these relations changed over development. An analysis of the children's errors also revealed complex interactions between these factors.
These data cannot be explained in full by existing theories of auxiliary acquisition. Researchers working within both generativist and constructivist frameworks need to develop more detailed theories of acquisition that predict the pattern of acquisition observed.
This study examined the perception of fundamental frequency (f0) patterns by Cantonese children with and without specific language impairment (SLI).
Participants were 14 five-year-old children with SLI, and 14 age-matched (AM) and 13 four-year-old vocabulary-matched (VM) controls. The children identified a word from familiar word pairs that illustrated the 8 minimally contrastive pairs of the 6 lexical tones. They discriminated the f0 patterns within contrastive tonal pairs in speech and nonspeech stimuli.
In tone identification, the SLI group performed worse than the AM group but not the VM group. In tone discrimination, the SLI group did worse than the AM group on 2 contrasts and showed a nonsignificant trend of poorer performance on all contrasts combined. The VM group generally did worse than the AM group. There were no group differences in discrimination performance between speech and nonspeech stimuli. No correlation was found between identification and discrimination performance. Only the normal controls showed a moderate correlation between vocabulary scores and performance in the 2 perception tasks.
The SLI group's poor tone identification cannot be accounted for by vocabulary knowledge alone. The group's tone discrimination performance suggests that some children with SLI have a deficit in f0 processing.
This study investigated whether adults with dyslexia show evidence of a consistent speech perception deficit by testing phoneme categorization and word perception in noise.
Seventeen adults with dyslexia and 20 average readers underwent a test battery including standardized reading, language and phonological awareness tests, and tests of speech perception. Categorization of a pea/bee voicing contrast was evaluated using adaptive identification and discrimination tasks, presented in quiet and in noise, and a fixed-step discrimination task. Two further tests of word perception in noise were presented.
There were no significant group differences for categorization in quiet or noise, across- and within-category discrimination as measured adaptively, or word perception, but average readers showed better across- and within-category discrimination in the fixed-step discrimination task. Individuals did not show consistent poor performance across related tasks.
The small number of group differences, and lack of consistent poor individual performance, suggests weak support for a speech perception deficit in dyslexia. It seems likely that at least some poor performances are attributable to nonsensory factors like attention. It may also be that some individuals with dyslexia have speech perceptual acuity that is at the lower end of the normal range and exacerbated by nonsensory factors.
The mandible is often portrayed as a primary structure of early babble production, but empiricists still need to specify (a) how mandibular motor control and kinematics vary among different types of multisyllabic babble, (b) whether chewing or jaw oscillation relies on a coordinative infrastructure that can be exploited for early types of multisyllables, and (c) whether the organization of motor control and associated kinematics varies across the nonspeech behaviors that are candidate motor stereotypies for speech.
Electromyographic signals were obtained from mandibular muscle groups, and associated kinematics were measured longitudinally from a typically developing infant from 9 to 22 months during jaw oscillation, chewing, and several types of early multisyllabic babble.
Measures of early motor control and mandibular kinematics for multisyllabic productions indicated task-dependent changes across syllable types and significant differences across babble and nonspeech behaviors. Differences in motor control were also observed across nonspeech behaviors.
Motor control for babble appears to be influenced by the balanced interaction between developing motor and linguistic systems, such that variation in linguistic complexity systematically evinces changes in motor organization apparently to meet these demands. This same effect was noted among chewing and jaw oscillation; task-dependent changes in mandibular control were noted across behaviors.
To examine several cognitive and perceptual abilities—including working memory (WM), information processing speed (PS), perceptual closure, and perceptual disembedding skill—as factors contributing to individual differences in lipreading performance and to examine how patterns in predictor variables change across age groups.
Forty-three younger adults (mean age = 20.8 years, SD = 2.4) and 38 older adults (mean age = 76.8 years, SD = 5.6) completed tasks measuring lipreading ability, verbal WM, spatial WM (SWM), PS, and perceptual abilities.
Younger adults demonstrated superior lipreading ability and perceptual skills compared with older adults. In addition, younger participants exhibited longer WM spans and faster PS than did the older participants. SWM and PS accounted for a significant proportion of the variance in lipreading ability in both younger and older adults, and the pattern of predictor variables remained consistent over age groups.
These findings suggest that the large individual variability in lipreading ability can be explained, in part, by individual differences in SWM and PS. Furthermore, as both of these abilities are known to decline with age, the findings suggest that age-related impairments in either or both of these abilities may account for the poorer lipreading ability of older compared with younger adults.
Functional orofacial behaviors vary in their force endpoint and rate of recruitment. This study assessed the gating of orofacial cutaneous somatosensation during different cyclic lip force recruitment rates. Understanding how differences in the rate of force recruitment influences trigeminal system function is an important step toward furthering the knowledge of orofacial sensorimotor control.
Lower lip vibrotactile detection thresholds (LL-VDTs) were sampled in response to sinusoidal inputs delivered to the lip vermilion at 5, 10, 50, and 150 Hz while adult participants engaged in a baseline condition (no force), 2 low-level lip force recruitment tasks differing by rate (0.1 Hz or 2 Hz), and passive displacement of the lip as a control to approximate the mechanosensory consequences of voluntary movement.
LL-VDTs increased significantly for test frequencies at or below 50 Hz during voluntary lip force recruitment. LL-VDT shifts were positively related to changes in the rate of lip force recruitment, whereas passively imposed displacements of the lip were ineffective in shifting LL-VDTs.
These findings are considered in relation to published reports of force-related sensory gating in orofacial and limb systems and the potential role of somatosensory gating along the trigeminal system during orofacial behaviors.
This investigation addressed two main questions: (a) How do toddlers' spoken utterances change during the first year of cochlear implant (CI) use? and (b) How do the time-courses for reaching spoken word milestones after implant activation compare with those reported for typically developing children? These questions were explored to increase understanding of early semantic development in children who receive CIs before their second birthdays.
Monthly recordings of mother-child interactions were gathered during the first year of CI use by a boy and a girl whose CIs were activated at 11 and 21 months of age, respectively. Child utterances were classified as nonwords, pre-words, single words, or word combinations, and the percentages of these utterance types were calculated for each month. Data were compared to published findings for typically developing children for the number of months of robust hearing (i.e., auditory access to conversational speech) needed to reach spoken word milestones and the chronological ages at which milestones were achieved.
The main findings were that the percentages of nonwords and pre-words decreased as single words and word combinations increased. Both children achieved most spoken word milestones with fewer months of robust hearing experience than reported for typically developing children; the youngest recipient achieved more milestones within typical age ranges than the child implanted later in life.
The children's expeditious gains in spoken word development appeared to be facilitated by interactions among their pre-implant hearing experiences; their relatively advanced physical, cognitive, and social maturity; participation in intervention programs; and the introduction of robust hearing within the Utterance Acquisition phase of language development according to the neurolingusitic theory (
Childhood apraxia of speech (CAS) has been associated with a wide variety of diagnostic descriptions and has been shown to involve different symptoms during successive stages of development. In the present study, the authors attempted to associate the symptoms of CAS in a particular developmental stage with particular information-processing deficits by using computational modeling with the Directions Into Velocities of Articulators (DIVA) model. The hypothesis was that the speech production system in CAS suffers from poor feed-forward control and, consequently, an increased reliance on the feedback control subsystem.
In a series of computer simulations, the authors systematically varied the ratio between feed-forward and feedback control during production attempts in the acquisition of feed-forward motor commands. The simulations were evaluated acoustically on 4 selected key symptoms of CAS.
Results showed that increasing the reliance on feedback control causes increased severity of these 4 symptoms of CAS: deviant coarticulation, speech sound distortion, searching articulation, and increased variability.
The findings support the idea that the key symptoms found in CAS could result from an increased reliance on feedback control due to poor feed-forward commands. Two possible root causes of degraded feed-forward control in CAS are discussed: reduced somatosensory information and increased levels of neural noise.
The purpose of this study was to determine whether the underlying temperamental structure of the Dutch Children's Behavior Questionnaire (CBQ;
A principal axis factor analysis was performed on data obtained with the Dutch CBQ from 69 CWS, 149 TDC, and 41 CWVN. All children were between the ages of 3;0 (years;months) and 8;11.
Results indicated a 3-factor solution, identified as Extraversion/Surgency, Negative Affect, and Effortful Control, for each of the participant groups, showing considerable similarity to previously published U.S., Chinese, Japanese, and Dutch samples. Congruence coefficients were highest for CWS and TDC and somewhat more modest when comparing CWVN and TDC. The Effortful Control factor consistently yielded the lowest congruence coefficients.
These data confirm that although stuttering, voice-disordered, and typically developing children may differ quantitatively with regard to mean scores on temperament scales, they are similar in terms of their overall underlying temperament structure. The equivalence of temperament structure provides a basis for further comparison of mean group scores on the individual temperament scales.
To test the hypotheses that adults who stutter will be slower in producing syntactically complex sentences than fluent adults and will benefit more from sentence-structure priming than will fluent adults.
Adults who stutter (n = 15) and fluent adults (n = 15) participated in 2 experiments. In Experiment 1, adults in both groups were administered a task that required memorization and production of sentences that varied in syntactic complexity. The same individuals who participated in Experiment 1 also participated in Experiment 2. The second experiment required all participants to create and produce sentences under primed and unprimed sentence-structure conditions.
Relative to adults who do not stutter, the speech initiation time of fluent utterances of adults who stutter became increasingly slower as syntactic complexity increased, and they exhibited greater facilitative effects of sentence-structure priming. In addition, adults who stutter showed a significant correlation between syntactic complexity and priming facilitation.
Data from these experiments confirmed both hypotheses and provided evidence that a subgroup of adults who stutter have grammatical encoding differences when compared with adults who do not stutter.
This study aimed to compare 2 quantitative acoustic measures of nasality in children with cleft lip and palate (CLP) and healthy controls using formalized perceptual assessment as a guide.
Fifty participants (23 children with CLP and 27 age- and gender-matched healthy controls) aged between 4 and 12 years produced a variety of high and low vowels that allowed perceptual ratings of nasal resonance severity as well as acoustic analysis of spectral changes. Two objective measures of nasality were used: 1/3 octave spectra analysis and the voice low tone high tone ratio. Each respective technique has been evaluated in previous research, and their potential as an effective means of detecting changes in nasal resonance has been demonstrated.
Only 1/3 octave spectra analysis differentiated between participants with hypernasal speech and those perceived to have normal nasal resonance. Significant differences were also observed between varying levels of perceived severity on vowels within nonnasalized phonemic environments (/p
Perceptual judgment remains the primary means of evaluating levels of nasality in children with CLP. However, the development and validation of easy-to-use objective techniques remains an important goal for effective clinical and empirical practice.
In this article, the authors report a case of acquired stuttering associated with Parkinson's disease (PD) that was responsive to unilateral subthalamic nucleus deep-brain stimulation (STN DBS) in the language-dominant hemisphere.
A single-subject, masked, multiple baseline design was used to evaluate the effects of unilateral left STN DBS on stuttering associated with PD. The patient underwent 3 formal speech assessments of spontaneous speech and the reading of passages with DBS off and on. Speech samples were videotaped and placed in random order, and 2 independent speech-language pathologists calculated the percentage of stuttered syllables and classified individual stuttering events.
Stuttering improved significantly in the DBS-on condition. In total, 10% of syllables were affected by stuttering events with DBS off, and less than 1% of syllables were affected by stuttering events with DBS on (n = 2,281 syllables, p < .00001, in a 2 test). The effect of unilateral STN DBS on stuttering was relatively independent of whether the patient was on or off dopaminergic medications.
This article emphasizes the important role of the subthalamic region in the motor control of speech and language.
To evaluate and compare the performance of 2 methods of voice activity detection (neck-attached accelerometer vs. binaural recordings) in field studies in environments where voice activity normally occurs.
A group of 11 healthy adults wore recording equipment during their lunch break. We used binary classification to analyze the results from the 2 methods. The output was compared to a gold standard, obtained through listening tests, and the probability for sensitivity (Ps) and false positive (Pf) was rated. The binary classifiers were set for consistent sensitivity of 99%; thus, the lower false positive rate would indicate the method with the better performance.
The neck-attached accelerometer (Pf = 0.5%) performed significantly (p < .001) better than the binaural method (Pf = 7%).
The neck-attached accelerometer is more suitable than the binaural method for voice assessments in environments where people are speaking in close proximity to each other and where the signal-to-noise ratio is moderate to low.