Prosodic modulation in the babble of cochlear implanted and normally hearing infants: a perceptua... more Prosodic modulation in the babble of cochlear implanted and normally hearing infants: a perceptual study using a visual analogue scale.
In early word productions, the same types of errors are manifest in children with cochlear implan... more In early word productions, the same types of errors are manifest in children with cochlear implants (CI) as in their normally hearing (NH) peers with respect to consonant clusters. However, the incidence of those types and their longitudinal development has not been examined nor quantified in the literature thus far. Furthermore, studies on the spontaneous speech of Dutch-speaking children with CI are missing. Here we compare children with CI and NH children with respect to their use of word-initial two-consonant clusters and the frequency of each type of error. The spontaneous speech of 9 Dutch-speaking children with CI and an age-matched cohort of NH children was analysed from word-onset up to age seven. Results showed that accuracy and frequency of consonant clusters increases with age and that the age at implant activation is crucial in children with CI. Cross-sectional comparisons showed that some aspects of consonant cluster production in children with CI lag behind that of their NH peers, but that children with CI catch up by age five.
International Journal of Pediatric Otorhinolaryngology, Apr 1, 2019
Auditory brainstem implantation (ABI) is a recent technique in children's hearing restoration. Up... more Auditory brainstem implantation (ABI) is a recent technique in children's hearing restoration. Up till now the focus in the literature has mainly been the perceptual outcomes after implantation, whereas the effect of ABI on spoken language is still an almost unexplored area of research. This study presents a one-year follow-up of the volubility of two children with ABI. The volubility of signed and oral productions is investigated and oral productions are examined in more detail. Results show clear developmental trends in both children, indicating a beneficial effect of ABI on spoken language development.
The aim of this study was to investigate the acoustic vowel space area in infant directed speech ... more The aim of this study was to investigate the acoustic vowel space area in infant directed speech (IDS). The research question is whether the vowel space is expanded or remains constant in IDS. A corpus of spontaneous interactions of 9 dyads followed monthly from the age of 6 to 24 months was analyzed. The occurrences in the parents' speech of each word that the children eventually acquired were extracted. The surface of the vowel triangle and the convex hull of all vowels were computed. The main result is that the development of the vowel space in IDS follows an inverted U-shaped curve: the vowel space starts relatively small, gradually increases as the child's first word use approaches, and decreases again afterwards. These findings show that parents adapt their articulation to the evolving linguistic abilities of their child, and this adaptation can be detected at the level of individual lexical items.
Do parents fine-tune the MLU of utterances with a particular word as the word is on the verge of ... more Do parents fine-tune the MLU of utterances with a particular word as the word is on the verge of appearing in the child's production? We analyzed a corpus of spontaneous interactions of 30 dyads. The children were in the initial stages of their lexical development, and the parents' utterances containing the words the children eventually acquired were selected. The main finding is that the MLU of the parental utterances containing the target words gradually decreased up to the point of the children's first production of those words. This suggests that parents fine-tune their utterances to support the children's linguistic development.
Dit onderzoek bestudeert de relatie tussen spreeksnelheid en de duur van de svarabhaktivocalen in... more Dit onderzoek bestudeert de relatie tussen spreeksnelheid en de duur van de svarabhaktivocalen in het Nederlands. Hierbij werd gebruik gemaakt van de spontane spraak van 160 leerkrachten Nederlands, gelijk verdeeld over vier verschillende regio's in Vlaanderen en Nederland. Het corpus omvatte gesproken taal van evenveel mannen als vrouwen. Er werd gefocust op 750 woorden die een consonantencluster bevatten met als eerste element een r en als tweede element een niet-alveolaire consonant of een n, en die na invoeging van een svarabhaktivocaal twee of drie syllaben tellen (bv. werk > [wɛrək], werken > [wɛrəkən]). Voor deze woorden werd de spreeksnelheid en de duur van de ingelaste svarabhaktivocaal gemeten. Zoals verwacht laten de resultaten van deze studie een duidelijk verband zien tussen spreeksnelheid en de duur van de svarabhaktivocaal: snellere spraak levert kortere svarabhaktivocalen op. Naast deze algemene trend is er ook een statistisch significant effect van regio, het aantal syllaben, de articulatieplaats van r en het tweede element van het consonantencluster. Verder was er een significante interactie tussen spreeksnelheid en de duur van sjwa bij mannen en vrouwen: vrouwen produceren in snelle spraak kortere svarabhaktivocalen dan mannen, terwijl hun sjwa's in trage spraak wat langer duren dan die van mannen. De verschillen in de duur van sjwa met betrekking tot spreeksnelheid zijn dus bij vrouwen meer uitgesproken dan bij mannen. Dit zou kunnen worden verklaard doordat de vrouwen-die doorgaans wat langere vocalen produceren-in snelle spraak articulatorische afstanden vlugger kunnen overbruggen dan mannen.
Purpose: The aim of the present study was to explore fine lexical tuning in Dutch infant-directed... more Purpose: The aim of the present study was to explore fine lexical tuning in Dutch infant-directed speech (IDS) addressed to congenitally deaf infants who received a cochlear implant (CI) early in life (<2 years of age) in comparison with children with normal hearing (NH). The longitudinal pattern of parents' utterance length in the initial stages of the child's lexical development was examined. Parents' utterances containing the words the children eventually acquired in the earliest developmental stages were selected and their MLU (Mean Length of Utterance) was measured.Method: Transcriptions of monthly recordings of spontaneous interactions of 10 CI children and 30 NH children with their parents were analyzed. The children with CI were followed from the moment their device was switched on, and the NH children from the age of 6 months onwards. A total of 57,846 utterances of parents of CI children and 149,468 utterances of parents of NH children were analyzed.Results:...
Objectives: This longitudinal study examined the impact of emerging vocabulary production on the ... more Objectives: This longitudinal study examined the impact of emerging vocabulary production on the ability to produce the phonetic cues to prosodic prominence in babbled and lexical disyllables of infants with Cochlear Implants (CI) and normally hearing infants (NH). Current research on typical language acquisition emphasizes the importance of vocabulary development for phonological and phonetic acquisition. Children with cochlear implants (CI) experience significant difficulties with the perception and production of prosody, and the role of possible top-down effects is therefore particularly relevant for this population. Design: Isolated disyllabic babble and first words were identified and segmented in longitudinal audio-video recordings and transcriptions for 9 NH infants and 9 infants with CI interacting with their parents. Monthly recordings were included from the onset of babbling until children had reached a cumulative vocabulary of 200 words. Three cues to prosodic prominence, F0, intensity and duration, were measured in the vocalic portions of stand-alone disyllables. In order to represent the degree of prosodic differentiation between two syllables in an utterance, the raw values for intensity and duration were transformed to ratios, and for f0 a measure of the perceptual distance in semitones was derived. The degree of prosodic differentiation for disyllabic babble and words for each cue was compared between groups. In addition, group and individual tendencies on the types of stress patterns for babble and words were also examined. 2 Results: The CI group had overall smaller pitch and intensity distances than the NH group. For the NH group, words had greater pitch and intensity distances than babbled disyllables. Especially for pitch distance, this was accompanied by a shift towards a more clearly expressed stress pattern that reflected the influence of the ambient language. For the CI group, the same expansion in words did not take place for pitch. For intensity, the CI group gave evidence of some increase of prosodic differentiation. The results for the duration measure showed evidence of utterance-final lengthening in both groups. In words, the CI group significantly reduced durational differences between syllables so that a more even-timed, less differentiated pattern emerged. Conclusions: The onset of vocabulary production did not have the same facilitatory effect for the CI infants on the production of phonetic cues for prosody, especially for pitch. It was argued that the results for duration may reflect greater articulatory difficulties in words for the CI group than the NH group. It was suggested that the lack of clear top-down effects of the vocabulary in the CI group may be due to a lag in development caused by an initial lack of auditory stimulation, possibly compounded by the absence of auditory feedback during the babble phase.
Foundations of the root category: analyses of linguistic input to Hebrew-speaking children. In R.... more Foundations of the root category: analyses of linguistic input to Hebrew-speaking children. In R. Berman (ed.
Previous studies have suggested that children possess cognitive representations of multi-word uni... more Previous studies have suggested that children possess cognitive representations of multi-word units (MWUs) and that MWUs can facilitate the acquisition of smaller units contained within them. We propose that the formation of MWU representations precedes and facilitates the formation of single-word representations in children. Using different computational methods, we extract MWUs from two large corpora of English childdirected speech. In subsequent regression analyses, we use age of first production of individual words as the dependent and the number of MWUs within which each word appears as an independent variable. We find that early-learned words appear within many MWUs – an effect which is neither reducible to frequency or other common co-variates, nor to the number of context words contained in the MWUs. Our findings support accounts wherein children acquire linguistic patterns of varying sizes, moving gradually from the discovery of MWUs to the acquisition of small-grained ling...
This study investigates the relationship between speech tempo and the duration of epentheticschwa... more This study investigates the relationship between speech tempo and the duration of epentheticschwa in Dutch. The speech materials consisted of the spontaneous speech of 160 teachers of Dutch: these speakers were equally distributed over four different regions in Belgium and the Netherlands. There were an equal number of men and women. The research focus was on 750words which contained a consonant cluster with ras the first element and a non-alveolar consonant or nas the second element. These words consisted of two or three syllables after schwa insertion (e.g., werk‘work’ > [wɛrək], werken‘to work’ > [wɛrəkən]). The speech rate of these words was calculated and the duration of any inserted schwa was measured. As predicted, the results show a clear relationship between speech rate and the duration of schwa: faster speech yields shorter schwas. Besides this general trend a statistically significant effect was found of geographical region, the number of syllables, the place of art...
This study investigates the learning mechanisms underlying the acquisition of a dialect as a seco... more This study investigates the learning mechanisms underlying the acquisition of a dialect as a second language. We focus on the acquisition of phonological features of a Flemish dialect by children with Standard Dutch or a regional variety of Dutch as their first language. Data were gathered by means of picture naming and sentence completion tasks. Inspired by Chambers (1992), who found that the data of second dialect learners displayed S-curve patterns which he interpreted as evidence of rule-based learning, we examine whether similar S-curves can be observed in the learner data of our subjects. Contrary to Chambers, our subjects’ data do not display S-curves but bear evidence of word-by-word learning across the board. These data are consistent with analogical memory-based models of language acquisition. In order to further investigate the applicability of memory-based reasoning to our data, we perform a computational classification task in TiMBL (Daelemans & Van den Bosch, 2005), in...
In this study, results of computational simulations on English child-directed speech are presente... more In this study, results of computational simulations on English child-directed speech are presented to uncover what distributional properties of words make it easier to group them into lexical categories. This analysis provides evidence that words are easier to categorize when (i) they are hard to predict given the contexts they occur in; (ii) they occur in few different contexts; and (iii) their contextual distributions have a low entropy, meaning that they tend to occur more often in one of the contexts they occur in. This profile fits that of content words, especially nouns and verbs, which is consistent with developmental evidence showing that children learning English start by forming a noun and a verb category. These results further characterize the role of distributional information in lexical category acquisition and confirm that it is a robust, reliable, and developmentally plausible source to learn lexical categories.
Prosodic modulation in the babble of cochlear implanted and normally hearing infants: a perceptua... more Prosodic modulation in the babble of cochlear implanted and normally hearing infants: a perceptual study using a visual analogue scale.
In early word productions, the same types of errors are manifest in children with cochlear implan... more In early word productions, the same types of errors are manifest in children with cochlear implants (CI) as in their normally hearing (NH) peers with respect to consonant clusters. However, the incidence of those types and their longitudinal development has not been examined nor quantified in the literature thus far. Furthermore, studies on the spontaneous speech of Dutch-speaking children with CI are missing. Here we compare children with CI and NH children with respect to their use of word-initial two-consonant clusters and the frequency of each type of error. The spontaneous speech of 9 Dutch-speaking children with CI and an age-matched cohort of NH children was analysed from word-onset up to age seven. Results showed that accuracy and frequency of consonant clusters increases with age and that the age at implant activation is crucial in children with CI. Cross-sectional comparisons showed that some aspects of consonant cluster production in children with CI lag behind that of their NH peers, but that children with CI catch up by age five.
International Journal of Pediatric Otorhinolaryngology, Apr 1, 2019
Auditory brainstem implantation (ABI) is a recent technique in children's hearing restoration. Up... more Auditory brainstem implantation (ABI) is a recent technique in children's hearing restoration. Up till now the focus in the literature has mainly been the perceptual outcomes after implantation, whereas the effect of ABI on spoken language is still an almost unexplored area of research. This study presents a one-year follow-up of the volubility of two children with ABI. The volubility of signed and oral productions is investigated and oral productions are examined in more detail. Results show clear developmental trends in both children, indicating a beneficial effect of ABI on spoken language development.
The aim of this study was to investigate the acoustic vowel space area in infant directed speech ... more The aim of this study was to investigate the acoustic vowel space area in infant directed speech (IDS). The research question is whether the vowel space is expanded or remains constant in IDS. A corpus of spontaneous interactions of 9 dyads followed monthly from the age of 6 to 24 months was analyzed. The occurrences in the parents' speech of each word that the children eventually acquired were extracted. The surface of the vowel triangle and the convex hull of all vowels were computed. The main result is that the development of the vowel space in IDS follows an inverted U-shaped curve: the vowel space starts relatively small, gradually increases as the child's first word use approaches, and decreases again afterwards. These findings show that parents adapt their articulation to the evolving linguistic abilities of their child, and this adaptation can be detected at the level of individual lexical items.
Do parents fine-tune the MLU of utterances with a particular word as the word is on the verge of ... more Do parents fine-tune the MLU of utterances with a particular word as the word is on the verge of appearing in the child's production? We analyzed a corpus of spontaneous interactions of 30 dyads. The children were in the initial stages of their lexical development, and the parents' utterances containing the words the children eventually acquired were selected. The main finding is that the MLU of the parental utterances containing the target words gradually decreased up to the point of the children's first production of those words. This suggests that parents fine-tune their utterances to support the children's linguistic development.
Dit onderzoek bestudeert de relatie tussen spreeksnelheid en de duur van de svarabhaktivocalen in... more Dit onderzoek bestudeert de relatie tussen spreeksnelheid en de duur van de svarabhaktivocalen in het Nederlands. Hierbij werd gebruik gemaakt van de spontane spraak van 160 leerkrachten Nederlands, gelijk verdeeld over vier verschillende regio's in Vlaanderen en Nederland. Het corpus omvatte gesproken taal van evenveel mannen als vrouwen. Er werd gefocust op 750 woorden die een consonantencluster bevatten met als eerste element een r en als tweede element een niet-alveolaire consonant of een n, en die na invoeging van een svarabhaktivocaal twee of drie syllaben tellen (bv. werk > [wɛrək], werken > [wɛrəkən]). Voor deze woorden werd de spreeksnelheid en de duur van de ingelaste svarabhaktivocaal gemeten. Zoals verwacht laten de resultaten van deze studie een duidelijk verband zien tussen spreeksnelheid en de duur van de svarabhaktivocaal: snellere spraak levert kortere svarabhaktivocalen op. Naast deze algemene trend is er ook een statistisch significant effect van regio, het aantal syllaben, de articulatieplaats van r en het tweede element van het consonantencluster. Verder was er een significante interactie tussen spreeksnelheid en de duur van sjwa bij mannen en vrouwen: vrouwen produceren in snelle spraak kortere svarabhaktivocalen dan mannen, terwijl hun sjwa's in trage spraak wat langer duren dan die van mannen. De verschillen in de duur van sjwa met betrekking tot spreeksnelheid zijn dus bij vrouwen meer uitgesproken dan bij mannen. Dit zou kunnen worden verklaard doordat de vrouwen-die doorgaans wat langere vocalen produceren-in snelle spraak articulatorische afstanden vlugger kunnen overbruggen dan mannen.
Purpose: The aim of the present study was to explore fine lexical tuning in Dutch infant-directed... more Purpose: The aim of the present study was to explore fine lexical tuning in Dutch infant-directed speech (IDS) addressed to congenitally deaf infants who received a cochlear implant (CI) early in life (<2 years of age) in comparison with children with normal hearing (NH). The longitudinal pattern of parents' utterance length in the initial stages of the child's lexical development was examined. Parents' utterances containing the words the children eventually acquired in the earliest developmental stages were selected and their MLU (Mean Length of Utterance) was measured.Method: Transcriptions of monthly recordings of spontaneous interactions of 10 CI children and 30 NH children with their parents were analyzed. The children with CI were followed from the moment their device was switched on, and the NH children from the age of 6 months onwards. A total of 57,846 utterances of parents of CI children and 149,468 utterances of parents of NH children were analyzed.Results:...
Objectives: This longitudinal study examined the impact of emerging vocabulary production on the ... more Objectives: This longitudinal study examined the impact of emerging vocabulary production on the ability to produce the phonetic cues to prosodic prominence in babbled and lexical disyllables of infants with Cochlear Implants (CI) and normally hearing infants (NH). Current research on typical language acquisition emphasizes the importance of vocabulary development for phonological and phonetic acquisition. Children with cochlear implants (CI) experience significant difficulties with the perception and production of prosody, and the role of possible top-down effects is therefore particularly relevant for this population. Design: Isolated disyllabic babble and first words were identified and segmented in longitudinal audio-video recordings and transcriptions for 9 NH infants and 9 infants with CI interacting with their parents. Monthly recordings were included from the onset of babbling until children had reached a cumulative vocabulary of 200 words. Three cues to prosodic prominence, F0, intensity and duration, were measured in the vocalic portions of stand-alone disyllables. In order to represent the degree of prosodic differentiation between two syllables in an utterance, the raw values for intensity and duration were transformed to ratios, and for f0 a measure of the perceptual distance in semitones was derived. The degree of prosodic differentiation for disyllabic babble and words for each cue was compared between groups. In addition, group and individual tendencies on the types of stress patterns for babble and words were also examined. 2 Results: The CI group had overall smaller pitch and intensity distances than the NH group. For the NH group, words had greater pitch and intensity distances than babbled disyllables. Especially for pitch distance, this was accompanied by a shift towards a more clearly expressed stress pattern that reflected the influence of the ambient language. For the CI group, the same expansion in words did not take place for pitch. For intensity, the CI group gave evidence of some increase of prosodic differentiation. The results for the duration measure showed evidence of utterance-final lengthening in both groups. In words, the CI group significantly reduced durational differences between syllables so that a more even-timed, less differentiated pattern emerged. Conclusions: The onset of vocabulary production did not have the same facilitatory effect for the CI infants on the production of phonetic cues for prosody, especially for pitch. It was argued that the results for duration may reflect greater articulatory difficulties in words for the CI group than the NH group. It was suggested that the lack of clear top-down effects of the vocabulary in the CI group may be due to a lag in development caused by an initial lack of auditory stimulation, possibly compounded by the absence of auditory feedback during the babble phase.
Foundations of the root category: analyses of linguistic input to Hebrew-speaking children. In R.... more Foundations of the root category: analyses of linguistic input to Hebrew-speaking children. In R. Berman (ed.
Previous studies have suggested that children possess cognitive representations of multi-word uni... more Previous studies have suggested that children possess cognitive representations of multi-word units (MWUs) and that MWUs can facilitate the acquisition of smaller units contained within them. We propose that the formation of MWU representations precedes and facilitates the formation of single-word representations in children. Using different computational methods, we extract MWUs from two large corpora of English childdirected speech. In subsequent regression analyses, we use age of first production of individual words as the dependent and the number of MWUs within which each word appears as an independent variable. We find that early-learned words appear within many MWUs – an effect which is neither reducible to frequency or other common co-variates, nor to the number of context words contained in the MWUs. Our findings support accounts wherein children acquire linguistic patterns of varying sizes, moving gradually from the discovery of MWUs to the acquisition of small-grained ling...
This study investigates the relationship between speech tempo and the duration of epentheticschwa... more This study investigates the relationship between speech tempo and the duration of epentheticschwa in Dutch. The speech materials consisted of the spontaneous speech of 160 teachers of Dutch: these speakers were equally distributed over four different regions in Belgium and the Netherlands. There were an equal number of men and women. The research focus was on 750words which contained a consonant cluster with ras the first element and a non-alveolar consonant or nas the second element. These words consisted of two or three syllables after schwa insertion (e.g., werk‘work’ > [wɛrək], werken‘to work’ > [wɛrəkən]). The speech rate of these words was calculated and the duration of any inserted schwa was measured. As predicted, the results show a clear relationship between speech rate and the duration of schwa: faster speech yields shorter schwas. Besides this general trend a statistically significant effect was found of geographical region, the number of syllables, the place of art...
This study investigates the learning mechanisms underlying the acquisition of a dialect as a seco... more This study investigates the learning mechanisms underlying the acquisition of a dialect as a second language. We focus on the acquisition of phonological features of a Flemish dialect by children with Standard Dutch or a regional variety of Dutch as their first language. Data were gathered by means of picture naming and sentence completion tasks. Inspired by Chambers (1992), who found that the data of second dialect learners displayed S-curve patterns which he interpreted as evidence of rule-based learning, we examine whether similar S-curves can be observed in the learner data of our subjects. Contrary to Chambers, our subjects’ data do not display S-curves but bear evidence of word-by-word learning across the board. These data are consistent with analogical memory-based models of language acquisition. In order to further investigate the applicability of memory-based reasoning to our data, we perform a computational classification task in TiMBL (Daelemans & Van den Bosch, 2005), in...
In this study, results of computational simulations on English child-directed speech are presente... more In this study, results of computational simulations on English child-directed speech are presented to uncover what distributional properties of words make it easier to group them into lexical categories. This analysis provides evidence that words are easier to categorize when (i) they are hard to predict given the contexts they occur in; (ii) they occur in few different contexts; and (iii) their contextual distributions have a low entropy, meaning that they tend to occur more often in one of the contexts they occur in. This profile fits that of content words, especially nouns and verbs, which is consistent with developmental evidence showing that children learning English start by forming a noun and a verb category. These results further characterize the role of distributional information in lexical category acquisition and confirm that it is a robust, reliable, and developmentally plausible source to learn lexical categories.
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