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1.
J Child Lang ; : 1-22, 2024 Feb 16.
Article in English | MEDLINE | ID: mdl-38362892

ABSTRACT

Children who receive cochlear implants develop spoken language on a protracted timescale. The home environment facilitates speech-language development, yet it is relatively unknown how the environment differs between children with cochlear implants and typical hearing. We matched eighteen preschoolers with implants (31-65 months) to two groups of children with typical hearing: by chronological age and hearing age. Each child completed a long-form, naturalistic audio recording of their home environment (appx. 16 hours/child; >730 hours of observation) to measure adult speech input, child vocal productivity, and caregiver-child interaction. Results showed that children with cochlear implants and typical hearing were exposed to and engaged in similar amounts of spoken language with caregivers. However, the home environment did not reflect developmental stages as closely for children with implants, or predict their speech outcomes as strongly. Home-based speech-language interventions should focus on the unique input-outcome relationships for this group of children with hearing loss.

2.
Dev Sci ; 26(4): e13364, 2023 07.
Article in English | MEDLINE | ID: mdl-36546681

ABSTRACT

Children with developmental language disorder (DLD) regularly use the bare form of verbs (e.g., dance) instead of inflected forms (e.g., danced). We propose an account of this behavior in which processing difficulties of children with DLD disproportionally affect processing novel inflected verbs in their input. Limited experience with inflection in novel contexts leads the inflection to face stronger competition from alternatives. Competition is resolved through a compensatory behavior that involves producing a more accessible alternative: in English, the bare form. We formalize this hypothesis within a probabilistic model that trades off context-dependent versus independent processing. Results show an over-reliance on preceding stem contexts when retrieving the inflection in a model that has difficulty with processing novel inflected forms. We further show that following the introduction of a bias to store and retrieve forms with preceding contexts, generalization in the typically developing (TD) models remains more or less stable, while the same bias in the DLD models exaggerates difficulties with generalization. Together, the results suggest that inconsistent use of inflectional morphemes by children with DLD could stem from inferences they make on the basis of data containing fewer novel inflected forms. Our account extends these findings to suggest that problems with detecting a form in novel contexts combined with a bias to rely on familiar contexts when retrieving a form could explain sequential planning difficulties in children with DLD. RESEARCH HIGHLIGHTS: Generalization difficulties with inflectional morphemes in children with Developmental Language Disorder arise from these children's limited experience with novel inflected forms. Limited experience with a form in novel contexts could lead to a storage bias where retrieving a form often requires relying on familiar preceding stems. While generalization in typically developing models remains stable across a range of model parameters, certain parameter values in the impaired models exaggerate difficulties with generalization. Children with DLD compensate for these retrieval difficulties through accessibility-driven language production: they produce the most accessible form among the alternatives.


Subject(s)
Language Development Disorders , Child , Humans , Language , Language Tests
3.
Child Dev ; 94(4): e197-e214, 2023.
Article in English | MEDLINE | ID: mdl-37036081

ABSTRACT

To learn language, children must map variable input to categories such as phones and words. How do children process variation and distinguish between variable pronunciations ("shoup" for soup) versus new words? The unique sensory experience of children with cochlear implants, who learn speech through their device's degraded signal, lends new insight into this question. In a mispronunciation sensitivity eyetracking task, children with implants (N = 33), and typical hearing (N = 24; 36-66 months; 36F, 19M; all non-Hispanic white), with larger vocabularies processed known words faster. But children with implants were less sensitive to mispronunciations than typical hearing controls. Thus, children of all hearing experiences use lexical knowledge to process familiar words but require detailed speech representations to process variable speech in real time.


Subject(s)
Cochlear Implantation , Cochlear Implants , Speech Perception , Child , Humans , Speech , Language
4.
J Exp Child Psychol ; 227: 105581, 2023 03.
Article in English | MEDLINE | ID: mdl-36423439

ABSTRACT

Although there is ample evidence documenting the development of spoken word recognition from infancy to adolescence, it is still unclear how development of word-level processing interacts with higher-level sentence processing, such as the use of lexical-semantic cues, to facilitate word recognition. We investigated how the ability to use an informative verb (e.g., draws) to predict an upcoming word (picture) and suppress competition from similar-sounding words (pickle) develops throughout the school-age years. Eye movements of children from two age groups (5-6 years and 9-10 years) were recorded while the children heard a sentence with an informative or neutral verb (The brother draws/gets the small picture) in which the final word matched one of a set of four pictures, one of which was a cohort competitor (pickle). Both groups demonstrated use of the informative verb to more quickly access the target word and suppress cohort competition. Although the age groups showed similar ability to use semantic context to facilitate processing, the older children demonstrated faster lexical access and more robust cohort suppression in both informative and uninformative contexts. This suggests that development of word-level processing facilitates access of top-down linguistic cues that support more efficient spoken language processing. Whereas developmental differences in the use of semantic context to facilitate lexical access were not explained by vocabulary knowledge, differences in the ability to suppress cohort competition were explained by vocabulary. This suggests a potential role for vocabulary knowledge in the resolution of lexical competition and perhaps the influence of lexical competition dynamics on vocabulary development.


Subject(s)
Speech Perception , Male , Child , Adolescent , Humans , Child, Preschool , Language , Semantics , Vocabulary , Linguistics
5.
Article in English | MEDLINE | ID: mdl-37902394

ABSTRACT

BACKGROUND: Children with phonological impairment present with pattern-based errors in their speech production. While some children have difficulties with speech perception and/or the establishment of robust underlying phonological representations, the nature of phonological impairment in children is still not well understood. Given that phonological and lexical development are closely linked, one way to better understand the nature of the problem in phonological impairment is to examine word learning abilities in children. AIMS: To examine word learning and its relationship with speech perception, speech production and vocabulary knowledge in children aged 4-5 years. There were two variables of interest: speech production abilities ranging from phonological impairment to typical speech; and vocabulary abilities ranging from typical to above average ('lexically precocious'). METHODS & PROCEDURES: Participants were 49 Australian-English-speaking children aged 48-69 months. Children were each taught four novel non-words (out of a selection of eight) through stories, and word learning was assessed at 1 week post-initial exposure. Word learning was assessed using two measures: confrontation naming and story retell naming. Data were analysed by group using independent-samples t-tests and Mann-Whitney U-tests, and continuously using multiple linear regression. OUTCOMES & RESULTS: There was no significant difference in word learning ability of children with and without phonological impairment, but regardless of speech group, children with above average vocabulary had significantly better word learning abilities than children with average vocabulary. In multiple linear regression, vocabulary was the only significant predictor of variance in word learning ability. CONCLUSIONS & IMPLICATIONS: Children with phonological impairment can be lexically precocious and learn new words like their peers without phonological impairment. Contrary to expectations, vocabulary knowledge rather than expressive phonological ability explained variance in measures of word learning. These findings question an assumption that children with phonological impairment have underspecified phonological representations. They also highlight the heterogeneity among children with phonological impairment and the need to better understand the nature of their difficulty learning the phonological system of the ambient language. WHAT THIS PAPER ADDS: What is already known on the subject There is limited research examining the word learning abilities of children with phonological impairment. Most previous research focuses on word properties such as phonotactic probability and neighbourhood density. Within the existing literature there are different reports and conclusions regarding the word learning abilities of children with phonological impairment and whether their word learning differs from that of children with typically developing speech. What this study adds to existing knowledge This study found that vocabulary was the strongest predictor of word learning across children with and without phonological impairment. There was no significant difference in word learning ability between children with and without phonological impairment. However, children with lexically precocious vocabulary abilities were significantly better at word learning than children with average vocabulary abilities. What are the potential or actual clinical implications of this work? Findings from this study support the importance of assessing and considering measures of word learning-including vocabulary-when working with children with phonological impairment. This study indicates that it is possible to use stories coupled with measures of confrontation naming and story retell to gain deeper insight into children's word learning abilities.

6.
Ear Hear ; 43(2): 519-530, 2022.
Article in English | MEDLINE | ID: mdl-34456300

ABSTRACT

OBJECTIVES: The present study investigated how development of the /t/-/k/ contrast is affected by the unique perceptual constraints imposed on young children using cochlear implants (CIs). We hypothesized that children with CIs would demonstrate unique patterns of speech acquisition due to device limitations, rather than straightforward delays due to a lack of auditory input in the first year of life before implantation. This study focused on the contrast between /t/ and /k/ because it is acquired early in the sequence of development, requires less advanced motor control than later-acquired place contrasts, is differentiated by spectral cues (which are particularly degraded when processed by CIs), and is not easily differentiated by visual cues alone. Furthermore, perceptual confusability between /t/ and /k/ may be exacerbated in front-vowel contexts, where the spectral energy for /k/ is shifted to higher frequencies, creating more spectral overlap with /t/. DESIGN: Children with CIs (n = 26; ages 31 to 66 mo) who received implants around their first birthdays were matched to peers with normal hearing (NH). Children participated in a picture-prompted auditory word-repetition task that included over 30 tokens of word-initial /t/ and /k/ consonants. Tokens were balanced across front-vowel and back-vowel contexts to assess the effects of coarticulation. Productions were transcribed and coded for accuracy as well as the types of errors produced (manner of articulation, voicing, or place of articulation errors). Centroid frequency was also calculated for /t/ and /k/ tokens that were produced correctly. Mixed-effects models were used to compare accuracy, types of errors, and centroid frequencies across groups, target consonants, and vowel contexts. RESULTS: Children with CIs produced /t/ and /k/ less accurately than their peers in both front- and back-vowel contexts. Children with CIs produced /t/ and /k/ with equal accuracy, and /k/ was produced less accurately in front-vowel contexts than in back-vowel contexts. When they produced errors, children with CIs were more likely to produce manner errors and less likely to produce voicing errors than children with NH. Centroid frequencies for /t/ and /k/ were similar across groups, except for /k/ in front-vowel contexts: children with NH produced /k/ in front-vowel contexts with higher centroid frequency than children with CIs, and they produced /k/ and /t/ with equal centroid frequencies in front-vowel contexts. CONCLUSIONS: Children with CIs not only produced /t/ and /k/ less accurately than peers with NH, they also demonstrated idiosyncratic patterns of acquisition, likely resulting from receiving degraded and distorted spectral information critical for differentiating /t/ and /k/. Speech-language pathologists should consider perceptual confusability of consonants (and their allophonic variations) during their assessment and treatment of this unique population of children.


Subject(s)
Cochlear Implantation , Cochlear Implants , Speech Perception , Adult , Aged , Child , Child, Preschool , Cochlear Implantation/methods , Hearing Tests , Humans , Middle Aged , Phonetics , Speech
7.
J Acoust Soc Am ; 150(3): 2256, 2021 09.
Article in English | MEDLINE | ID: mdl-34598599

ABSTRACT

Previous work has found that preschoolers with greater phonological awareness and larger lexicons, who speak more throughout the day, exhibit less intra-syllabic coarticulation in controlled speech production tasks. These findings suggest that both linguistic experience and speech-motor control are important predictors of spoken phonetic development. Still, it remains unclear how preschoolers' speech practice when they talk drives the development of coarticulation because children who talk more are likely to have both increased fine motor control and increased auditory feedback experience. Here, the potential effect of auditory feedback is studied by examining a population-children with cochlear implants (CIs)-which is naturally differing in auditory experience. The results show that (1) developmentally appropriate coarticulation improves with an increased hearing age but not chronological age; (2) children with CIs pattern coarticulatorily closer to their younger, hearing age-matched peers than chronological age-matched peers; and (3) the effects of speech practice on coarticulation, measured using naturalistic, at-home recordings of the children's speech production, only appear in the children with CIs after several years of hearing experience. Together, these results indicate a strong role of auditory feedback experience on coarticulation and suggest that parent-child communicative exchanges could stimulate children's own vocal output, which drives speech development.


Subject(s)
Cochlear Implantation , Cochlear Implants , Deafness , Speech Perception , Deafness/surgery , Feedback , Hearing , Humans , Phonetics
8.
J Child Lang ; 48(1): 31-54, 2021 01.
Article in English | MEDLINE | ID: mdl-32398187

ABSTRACT

This study examined a potential lexicality advantage in young children's early speech production: do children produce sound sequences less accurately in nonwords than real words? Children aged 3;3-4;4 completed two tasks: a real word repetition task and a corresponding nonword repetition task. Each of the 23 real words had a paired consonant-vowel sequence in the nonword in word-initial position (e.g., 'su' in ['sutkes] 'suitcase' and ['sudrɑs]). The word-initial consonant-vowel sequences were kept constant between the paired words. Previous work on this topic compared different sequences of paired sounds, making it hard to determine if those results were due to a lexical or phonetic effect. Our results show that children reliably produced consonant-vowel sequences in real words more accurately than nonwords. The effect was most pronounced in children with smaller receptive vocabularies. Together, these results reinforce theories arguing for interactions between vocabulary size and phonology in language development.


Subject(s)
Child Language , Language Development , Phonetics , Speech Perception , Vocabulary , Child, Preschool , Cognition , Female , Humans , Male , Minnesota , Wisconsin
9.
J Acoust Soc Am ; 146(6): EL516, 2019 12.
Article in English | MEDLINE | ID: mdl-31893765

ABSTRACT

Speech produced by children is characterized by a high fundamental frequency which complicates measurement of vocal tract resonances, and hence coarticulation. Here two whole-spectrum measures of coarticulation are validated, one temporal and one spectral, that are less sensitive to these challenges. Using these measures, consonant-vowel coarticulation is calculated in the speech of a large sample of 4-year-old children. The measurements replicate known lingual coarticulatory findings from the literature, demonstrating the utility of these acoustic measures of coarticulation in speakers of all ages.


Subject(s)
Speech Acoustics , Speech Production Measurement , Speech/physiology , Child, Preschool , Female , Humans , Male , Phonetics , Time Factors
10.
Dev Sci ; 21(6): e12685, 2018 11.
Article in English | MEDLINE | ID: mdl-29781230

ABSTRACT

Children learn words by listening to caregivers, and the quantity and quality of early language input predict later language development. Recent research suggests that word recognition efficiency may influence the relationship between input and vocabulary growth. We asked whether language input and lexical processing at 28-39 months predicted vocabulary size one year later in 109 preschoolers. Input was measured using adult word counts from LENA recordings. We used the visual world paradigm and measured lexical processing as the rate of change in proportion of looks to target. Regression analysis showed that lexical processing did not constrain the effect of input on vocabulary size. We also found that input and processing were more reliable predictors of receptive than expressive vocabulary growth.


Subject(s)
Language Development , Language , Vocabulary , Caregivers , Child , Child, Preschool , Humans , Learning , Regression Analysis
11.
J Acoust Soc Am ; 144(2): EL105, 2018 08.
Article in English | MEDLINE | ID: mdl-30180689

ABSTRACT

Dynamic spectral shape features accurately classify /t/ and /k/ productions across speakers and contexts. This paper shows that word-initial /t/ and /k/ tokens produced by 21 adults can be differentiated using a single, static spectral feature when spectral energy concentration is considered relative to expectations within a given speaker and vowel context. Centroid and peak frequency-calculated from both acoustic and psychoacoustic spectra-were compared to determine whether one feature could reliably differentiate /t/ and /k/, and, if so, which feature best differentiated them. Centroid frequency from both acoustic and psychoacoustic spectra accurately classified productions of /t/ and /k/.


Subject(s)
Phonetics , Speech Acoustics , Adult , Female , Humans , Male , Psychoacoustics , Speech Perception
12.
Ear Hear ; 38(1): 42-56, 2017.
Article in English | MEDLINE | ID: mdl-27556521

ABSTRACT

OBJECTIVES: Previous research has found that relative to their peers with normal hearing (NH), children with cochlear implants (CIs) produce the sibilant fricatives /s/ and /∫/ less accurately and with less subphonemic acoustic contrast. The present study sought to further investigate these differences across groups in two ways. First, subphonemic acoustic properties were investigated in terms of dynamic acoustic features that indexed more than just the contrast between /s/ and /∫/. Second, the authors investigated whether such differences in subphonemic acoustic contrast between sibilant fricatives affected the intelligibility of sibilant-initial single word productions by children with CIs and their peers with NH. DESIGN: In experiment 1, productions of /s/ and /∫/ in word-initial prevocalic contexts were elicited from 22 children with bilateral CIs (aged 4 to 7 years) who had at least 2 years of CI experience and from 22 chronological age-matched peers with NH. Acoustic features were measured from 17 points across the fricatives: peak frequency was measured to index the place of articulation contrast; spectral variance and amplitude drop were measured to index the degree of sibilance. These acoustic trajectories were fitted with growth-curve models to analyze time-varying spectral change. In experiment 2, phonemically accurate word productions that were elicited in experiment 1 were embedded within four-talker babble and played to 80 adult listeners with NH. Listeners were asked to repeat the words, and their accuracy rate was used as a measure of the intelligibility of the word productions. Regression analyses were run to test which acoustic properties measured in experiment 1 predicted the intelligibility scores from experiment 2. RESULTS: The peak frequency trajectories indicated that the children with CIs produced less acoustic contrast between /s/ and /∫/. Group differences were observed in terms of the dynamic aspects (i.e., the trajectory shapes) of the acoustic properties. In the productions by children with CIs, the peak frequency and the amplitude drop trajectories were shallower, and the spectral variance trajectories were more asymmetric, exhibiting greater increases in variance (i.e., reduced sibilance) near the fricative-vowel boundary. The listeners' responses to the word productions indicated that when produced by children with CIs, /∫/-initial words were significantly more intelligible than /s/-initial words. However, when produced by children with NH, /s/-initial words and /∫/-initial words were equally intelligible. Intelligibility was partially predicted from the acoustic properties (Cox & Snell pseudo-R > 0.190), and the significant predictors were predominantly dynamic, rather than static, ones. CONCLUSIONS: Productions from children with CIs differed from those produced by age-matched NH controls in terms of their subphonemic acoustic properties. The intelligibility of sibilant-initial single-word productions by children with CIs is sensitive to the place of articulation of the initial consonant (/∫/-initial words were more intelligible than /s/-initial words), but productions by children with NH were equally intelligible across both places of articulation. Therefore, children with CIs still exhibit differential production abilities for sibilant fricatives at an age when their NH peers do not.


Subject(s)
Cochlear Implantation/methods , Deafness/rehabilitation , Speech Acoustics , Speech Intelligibility , Acoustics , Child , Child, Preschool , Cochlear Implants , Female , Humans , Male , Phonetics , Speech
13.
Clin Linguist Phon ; 31(1): 80-103, 2017.
Article in English | MEDLINE | ID: mdl-27552446

ABSTRACT

Past studies have shown incontrovertible evidence for the existence of covert contrasts in children's speech, i.e. differences between target productions that are nonetheless transcribed with the same phonetic symbol. Moreover, there is evidence that these are relevant to forming prognoses and tracking progress in children with speech sound disorder. A challenge remains to determine the most efficient and reliable methods for assessing covert contrasts. This study investigates how readily listeners can identify covert contrasts in children's speech when using a continuous rating scale in the form of a visual analogue scale (VAS) to denote children's productions. Individual listeners' VAS responses were found to correlate statistically significantly with a variety of continuous measures of children's production accuracy, including judgements of binary accuracy pooled over a large set of listeners. These findings reinforce the growing body of evidence that VAS judgements are potentially useful clinical measures of covert contrast.


Subject(s)
Child Language , Speech Acoustics , Speech Perception/physiology , Speech Sound Disorder , Adult , Child , Female , Humans , Male , Phonetics , Surveys and Questionnaires
14.
Clin Linguist Phon ; 31(1): 56-79, 2017.
Article in English | MEDLINE | ID: mdl-27736242

ABSTRACT

Previous research has shown that continuous rating scales can be used to assess phonetic detail in children's productions, and could potentially be used to detect covert contrasts. Two experiments examined whether continuous rating scales have the additional benefit of being less susceptible to task-related biasing than categorical phonetic transcriptions. In both experiments, judgements of children's productions of /s/ and /θ/ were interleaved with two types of rating tasks designed to induce bias: continuous judgements of a parameter whose variation is itself relatively more continuous (gender typicality of their speech) in one biasing condition, and categorical judgements of a parameter that is relatively less continuous (the vowel they produced) in the other biasing condition. One experiment elicited continuous judgements of /s/ and /θ/ productions, while the other elicited categorical judgements. The results of Experiment 1 showed that the influence of acoustic characteristics on continuous judgements of /s/ and /θ/ was stable across biasing conditions. In contrast, the results of Experiment 2 showed that the influence of acoustic characteristics on categorical judgements of /s/ and /θ/differed systematically across biasing conditions. These results suggest that continuous judgements are psychometrically superior to categorical judgements, as they are more resistant to task-related bias.


Subject(s)
Speech Acoustics , Speech Perception , Speech Production Measurement , Adult , Bias , Female , Humans , Male , Phonetics , Surveys and Questionnaires
15.
Ear Hear ; 36(4): e153-65, 2015.
Article in English | MEDLINE | ID: mdl-25654299

ABSTRACT

OBJECTIVES: This study measured the impact of auditory spectral resolution on listening effort. Systematic degradation in spectral resolution was hypothesized to elicit corresponding systematic increases in pupil dilation, consistent with the notion of pupil dilation as a marker of cognitive load. DESIGN: Spectral resolution of sentences was varied with two different vocoders: (1) a noise-channel vocoder with a variable number of spectral channels; and (2) a vocoder designed to simulate front-end processing of a cochlear implant, including peak-picking channel selection with variable synthesis filter slopes to simulate spread of neural excitation. Pupil dilation was measured after subject-specific luminance adjustment and trial-specific baseline measures. Mixed-effects growth curve analysis was used to model pupillary responses over time. RESULTS: For both types of vocoder, pupil dilation grew with each successive degradation in spectral resolution. Within each condition, pupillary responses were not related to intelligibility scores, and the effect of spectral resolution on pupil dilation persisted even when only analyzing trials in which responses were 100% correct. CONCLUSIONS: Intelligibility scores alone were not sufficient to quantify the effort required to understand speech with poor resolution. Degraded spectral resolution results in increased effort required to understand speech, even when intelligibility is at 100%. Pupillary responses were a sensitive and highly granular measurement to reveal changes in listening effort. Pupillary responses might potentially reveal the benefits of aural prostheses that are not captured by speech intelligibility performance alone as well as the disadvantages that are overcome by increased listening effort.


Subject(s)
Noise , Pupil/physiology , Speech Perception/physiology , Acoustic Stimulation , Adolescent , Adult , Female , Humans , Male , Speech Discrimination Tests , Young Adult
16.
Lang Speech Hear Serv Sch ; 55(2): 598-606, 2024 04 11.
Article in English | MEDLINE | ID: mdl-38306497

ABSTRACT

PURPOSE: Clinicians are tasked with using culturally and linguistically appropriate tools to evaluate oral and written language development accurately. However, limited tools account for linguistic diversity in writing. This gap can lead to under- and overdiagnosis of students who speak nonmainstream dialects. This study addressed that gap by developing a writing task to identify nonmainstream dialect features in the writing of early elementary school students. We describe the development, feasibility, and results of pilot testing of the task. METHOD: One hundred fifty-one first and second graders participated in the study as part of a larger study of nonmainstream dialect use. Students completed standardized literacy and language assessments and the researcher-developed writing task. The writing task used a novel fill-in-the-blank format to identify morphological features that vary between Mainstream American English and nonmainstream varieties such as African American English. RESULTS: Second-grade students performed better on the writing task than first graders, and writing performance was strongly related to standardized literacy scores. Literacy skills were the strongest predictor of Mainstream American English use in writing, but spoken dialect use also correlated with written dialect use. CONCLUSIONS: The writing task captured dialect use in early elementary school students' writing, and students' performance on standardized literacy measures predicted written dialect features. These results are a first step toward developing a standardized measure to help professionals appropriately diagnose written expression disorders within linguistically diverse students. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25079891.


Subject(s)
Black or African American , Language , Humans , Language Tests , Students , Writing
17.
Am J Speech Lang Pathol ; : 1-19, 2024 Jul 19.
Article in English | MEDLINE | ID: mdl-39028570

ABSTRACT

PURPOSE: The purpose of this study was to describe the speech production, speech perception, vocabulary, and word learning abilities of lexically precocious 4-year-old children with phonological impairment, in an effort to better understand the underlying nature of phonological impairment in children. METHOD: Using a case series approach, we identified four children with phonological impairment and precocious vocabulary abilities. Each child completed routine speech production and vocabulary assessments, as well as experimental speech perception and word learning tasks. The results from these tasks were then used to create profiles of each child's individual strengths and needs across the abilities assessed. RESULTS: Although all four children presented with phonological impairment and lexically precocious receptive and expressive vocabulary, they differed in their specific speech errors. One child presented with phonological speech errors only, while the other three children presented with an interdental lisp alongside their phonological errors. Three children presented with average speech perception abilities, and one child presented with poorer speech perception. The same three children also showed some learning of novel nonwords 1 week post-initial exposure, while the other child showed no evidence of word learning 1 week post-initial exposure. CONCLUSIONS: The clinical profiles of lexically precocious children with phonological impairment offered different insights into the nature of the problem. Although one child appeared to present with underspecified underlying representations of words, the other three children appeared to present with well-specified underlying representations. Of the three children with well-specified underlying representations, two appeared to have difficulty abstracting particular rules of the ambient phonological system. Further research is needed to improve our understanding of the underlying nature of phonological impairment. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.26307640.

18.
Cogn Sci ; 47(8): e13328, 2023 08.
Article in English | MEDLINE | ID: mdl-37622433

ABSTRACT

As children gradually master grammatical rules, they often go through a period of producing form-meaning associations that were not observed in the input. For example, 2- to 3-year-old English-learning children use the bare form of verbs in settings that require obligatory past tense meaning while already starting to produce the grammatical -ed inflection. While many studies have focused on overgeneralization errors, fewer studies have attempted to explain the root of this earlier stage of rule acquisition. In this work, we use computational modeling to replicate children's production behavior prior to the generalization of past tense production in English. We illustrate how seemingly erroneous productions emerge in a model, without being licensed in the grammar and despite the model aiming at conforming to grammatical forms. Our results show that bare form productions stem from a tension between two factors: (1) trying to produce a less frequent meaning (the past tense) and (2) being unable to restrict the production of frequent forms (the bare form) as learning progresses. Like children, our model goes through a stage of bare form production and then converges on adult-like production of the regular past tense, showing that these different stages can be accounted for through a single learning mechanism.


Subject(s)
Generalization, Psychological , Learning , Adult , Humans , Child , Child, Preschool , Computer Simulation , Linguistics
19.
J Speech Lang Hear Res ; 66(4): 1173-1191, 2023 04 12.
Article in English | MEDLINE | ID: mdl-36940475

ABSTRACT

PURPOSE: The purpose of this study was to explore the relationship between speech perception, speech production, and vocabulary abilities in children with and without speech sound disorders (SSDs), analyzing the data both by group and continuously. METHOD: Sixty-one Australian English-speaking children aged 48-69 months participated in this study. Children's speech production abilities ranged along the continuum from SSDs through to typical speech. Their vocabulary abilities ranged along the continuum from typical to above average ("lexically precocious"). Children completed routine speech and language assessments in addition to an experimental Australian English lexical and phonetic judgment task. RESULTS: When analyzing data by group, there was no significant difference between the speech perception ability of children with SSDs and that of children without SSDs. Children with above-average vocabularies had significantly better speech perception ability than children with average vocabularies. When analyzing data continuously, speech production and vocabulary were both significant positive predictors of variance in speech perception ability, both individually in simple linear regression and when combined in multiple linear regression. There was also a significant positive correlation between perception and production of two of the four target phonemes tested (i.e., /k/ and /ʃ/) among children in the SSD group. CONCLUSIONS: Results from this study provide further insight into the complex relationship between speech perception, speech production, and vocabulary abilities in children. While there is a clinical and important need for categorical distinctions between SSDs and typically developing speech, findings further highlight the value of investigating speech production and vocabulary abilities continuously and categorically. By capturing the heterogeneity among children's speech production and vocabulary abilities, we can advance our understanding of SSDs in children. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.22229674.


Subject(s)
Speech Perception , Speech , Humans , Child , Vocabulary , Australia , Phonetics
20.
J Acoust Soc Am ; 132(5): 3439-52, 2012 Nov.
Article in English | MEDLINE | ID: mdl-23145624

ABSTRACT

This study examined the phonetic realization of voiced stops in the Cretan and Thessalonikan dialects of Modern Greek. Six males and six females of each dialect were recorded in a sentence-reading task. Duration and amplitude were measured to compare the degree of nasality of voiced stops to that of nasals in different phonetic contexts. Results showed that amplitude changes during the voicing bar of the voiced stops varied both within and across speakers. In some instances, there was consistently low amplitude throughout the voicing bar (characteristic of voiced stops), whereas in other instances, there was high amplitude at the closure onset followed by decreasing amplitude toward the burst (characteristic of prenasalization). By contrast, nasals had consistently high amplitude throughout the murmur. The mixed-effects models suggest that there were complex and interactive influences of dialect, gender, prosodic position, and stress in realizing prenasality in the voiced stops. In particular, Cretan male speakers showed the least clear tendency of prenasalization consistent with earlier impressionistic studies. Furthermore, productions of Cretan males showed less prenasalization than those of females in both prosodic positions. The procedures in this study can be used to describe prenasalization in other dialects or languages where prenasalization has been observed.


Subject(s)
Phonetics , Speech Acoustics , Voice Quality , Adult , Female , Humans , Least-Squares Analysis , Linear Models , Male , Middle Aged , Pattern Recognition, Automated , Sex Factors , Signal Processing, Computer-Assisted , Sound Spectrography , Speech Production Measurement , Time Factors , Young Adult
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