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.

Speaking intelligibly is an important achievement in children’s language development. How far do congenitally severe-to-profound hearing-impaired children who received a cochlear implant (CI) in the first two years of their life advance on the path to intelligibility in comparison to children with typical hearing (NH)? Spontaneous speech samples of children with CI and children with NH were orthographically transcribed by naïve transcribers. The entropy of the transcriptions was computed to analyze their degree of uniformity. The same samples were also rated on a continuous rating scale by another group of adult listeners. The transcriptions of the NH children’s speech were more uniform, i.e., had significantly lower entropy, than those of the CI children, suggesting that the latter group displayed lower intelligibility. This was confirmed by the ratings on the continuous scale. Despite the relatively restricted age ranges, older children reached better intelligibility scores in both groups.

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.

This study examined early Hebrew verb acquisition, highlighting CDS–CS relations across inflectional and derivational verb learning. It was carried out on a corpus of longitudinal dense dyadic interactions of two Hebrew-speaking toddlers aged 1;8–2;2 and their parents. Findings revealed correlated patterns within and between CDS and CS corpora in terms of verbs, structural root categories, and their components (roots, binyan conjugations, and derivational verb families), and clear relations between lexical-derivational development and inflectional growth in input–output relations, measured by MSP. It also showed that both corpora had few, yet highly semantically coherent, derivational families. Lexical learning in Hebrew was shown to be morphologically oriented, with both inflectional and derivational learning supporting and being supported by the development of the verb lexicon. These findings support findings in the general literature regarding the close relationship between parental input and child speech, and the affinity between lexical and grammatical growth.

This study investigated the relation between lexical development and the production of prosodic prominence in disyllabic babble and words. Monthly recordings from nine typically developing Belgian-Dutch-speaking infants were analyzed from the onset of babbling until a cumulative vocabulary of 200 words was reached. The differentiation between the two syllables of isolated disyllabic utterances was computed for f0, intensity, and duration measurements. Results showed that the ambient trochaic pattern emerged in babble, but became enhanced in words. Words showed more prosodic differentiation in terms of f0 and intensity and a more even duration ratio. Age or vocabulary size did not predict the expansion of f0 or intensity in words, whereas vocabulary size was related to the production of more even-timed syllables. The findings are discussed in terms of lexicalist accounts of phonetic development and a potential phonetic highlighting function of first words.

The impact of input frequency (IF) and functional load (FL) of segments in the ambient language on the acquisition order of word-initial consonants is investigated. Several definitions of IF/FL are compared and implemented. The impact of IF/FL and their components are computed using a longitudinal corpus of interactions between thirty Dutch-speaking children (age range: 0 ; 6–2 ; 0) and their primary caretaker(s). The corpus study reveals significant correlations between IF/FL and acquisition order. The highest predictive values are found for the token frequency of segments, and for FL computed on minimally different word types in child-directed speech. Although IF and FL significantly correlate, they do have a different impact on the order of acquisition of word-initial consonants. When the impact of IF is partialed out, FL still has a significant correlation with acquisition order. The reverse is not true, suggesting that the acquisition of word-initial consonants is mainly influenced by their discriminating function.

Various measures for identifying the onset of babbling have been proposed in the literature, but a formal definition of the exact procedure and a thorough validation of the sample size required for reliably establishing babbling onset is lacking. In this paper the reliability of five commonly used measures is assessed using a large longitudinal corpus of spontaneous speech from forty infants (age 0 ; 6−2 ; 0). In a first experiment it is shown that establishing the onset of babbling with reasonable (95%) confidence is impossible when the measures are computed only once, and when the number of vocalizations are not equal for all children at all ages. In addition, each measure requires a different minimal sample size. In the second experiment a robust procedure is proposed and formally defined that permits the identification of the onset of babbling with 95% confidence. The bootstrapping procedure involves extensive resampling and requires relatively few data.

The Rideau Canal in Canada was constructed in the 1800s to enable strategic military andcommercial transport in eastern Ontario between Lake Ontario and the Ottawa River. Today,the Rideau Canal is managed by Parks Canada and remains an engineered ecosystem,particularly in the urban Ottawa reach (7 km long) where it is largely channelized and ispartially drained during the winter to protect canal infrastructure (i.e., locks) andprovide recreational opportunities (i.e., skating). Interestingly, the Ottawa reach of theRideau Canal supports one of the few wild urban muskellunge (Esoxmasquinongy) fisheries in North America supported by natural reproduction.However, little is known about the spatial ecology, residency patterns or survival of thisapex freshwater predator in urban environments or canal systems. Radio-telemetry was usedto study adult (N = 10; total size range of 64 to 122 cm) muskellunge inthe Ottawa reach of the Rideau Canal over a multiple year period. The seasonal movementsand home range of muskellunge were greatest during spring corresponding with the periodwhen water levels in the canal were raised and muskellunge were presumably seeking outsuitable spawning habitats following ice-off. During the summer fish ranged throughout theentire 7 km urban reach of the canal and by early fall muskellunge moved to the deeperparts of the reach and became largely restricted to an embayment known as Dow’s Lake priorto the lowering of the canal where they stayed for the entire winter. The same pattern ofseasonal movements persisted across several years. None of the tagged muskellunge werestranded from the fall canal drainage. One fish emigrated from the urban reach of thecanal during the study period, moving upstream through a lock to an exurban reach. Inaddition, a single tagged fish died from a winterkill event. Environmental influences suchas seasonality and water depth (associated with canal operations) are believed to be theprimary mechanisms contributing to habitat selection and movement patterns of muskellungein this reach of the Rideau Canal. Data on the spatial ecology of muskellunge in the urbanreaches of the Rideau Canal will inform management of this unique population of fish toensure that the historic and ecological values are balanced to preserve this iconicCanadian natural heritage site and its biota.

Traditional software development methodologies enhanced by a clinical component result in information systems that support the practice of nursing. This paper describes the clinical informatics model used to develop and evaluate a mobile computer assessment tool. Data entry of atomic-level elements, with storage in a relational database, allows the synthesis and analysis by multiple disciplines to aid in real-time decision making. The system is designed to improve the recording and accessibility of patient data and nursing observations on a geriatric unit at the Salt Lake VA Medical Center.

Intuitive syllabifications of 50 five- and six- and 50 eight-year-old children are studied in an experimental setting. The children syllabified Dutch disyllabic words with a single intervocalic consonant that were presented orally to them. The aim was to find out if these syllabifications adhered to the universal principles of syllable structure and if the children's syllabifications witnessed an overruling of the universal phonological constraints by language specific ones. Results indicate that universal principles are sufficient to explain syllabifications. Except for obligatory onset formation, other principles act as soft constraints that are influenced by factors such as stress and vowel and consonant quality. A language specific constraint proposed in the phonological literature, namely bimoraic minimality, is hypothesized to be a result of children's familiarization with the spelling conventions.

A longitudinal analysis is presented of the fillers of a Dutch-speaking child between 1 ; 10 and 2 ; 7. Our analysis corroborates familiar regularities reported in the literature: most fillers resemble articles in shape and distribution, and are affected by rhythmic and positional constraints. A novel finding is the impact of the lexical environment: particular function words act as ‘anchor’ words that attract occurrences of schwa fillers after them. The child inserts significantly more schwa fillers in these contexts. The anchor words are among the most frequent words preceding articles in the input, indicating a sharp sensitivity to such distributional regularities. Nasal fillers too are affected by distributional learning, but at the phonological level: the child first uses nasals before [h]-initial nouns, and then generalizes this usage to all [h]-initial words. These observations are related to the growing body of evidence for the impact of distributional learning on early language production.

The jumbo or Humboldt squid, Dosidicus gigas, is an important fisheries resource and a significant participant in regional ecologies as both predator and prey. It is the largest species in the oceanic squid family Ommastrephidae and has the largest known potential fecundity of any cephalopod, yet little is understood about its reproductive biology. We report the first discovery of a naturally deposited egg mass of Dosidicus gigas, as well as the first spawning of eggs in captivity. The egg mass was found in warm water (25–27°C) at a depth of 16 m and was far larger than the egg masses of any squid species previously reported. Eggs were embedded in a watery, gelatinous matrix and were individually surrounded by a unique envelope external to the chorion. This envelope was present in both wild and captive-spawned egg masses, but it was not present in artificially fertilized eggs. The wild egg mass appeared to be resistant to microbial infection, unlike the incomplete and damaged egg masses spawned in captivity, suggesting that the intact egg mass protects the eggs within. Chorion expansion was also more extensive in the wild egg mass. Hatchling behaviours included proboscis extension, chromatophore activity, and a range of swimming speeds that may allow them to exercise some control over their distribution in the wild.

Fikkert (1994) analyzed a large corpus of Dutch children's early language production, and found that they often add targetless syllables to their words in order to create bisyllabic feet. In this note we point out a methodological problem with that analysis: in an important number of cases, epenthetic vowels occur at places where grammatical morphemes (e.g. plural and diminutive suffixes) may be expected. Hence, the seemingly targetless syllables may represent grammatical morphemes. A reanalysis of Fikkert's original data reveals that her rhythmic explanation cannot be maintained if those cases are excluded from the analysis.

This study investigates the role of phonological and morphological information in children's developing orthographies in two languages with different linguistic typologies: Hebrew, a Semitic language with a highly synthetic morphology, and Dutch, a Germanic language with a sparse morphology.

192 Israeli and 192 Belgian monolingual schoolchildren in grades 1–6 (aged 6;0–12;0) were administered respective dictation tasks in which homophonous segments were the targets. In each language, these phonologically distinct segments are neutralized phonetically but are nevertheless represented orthographically. In both languages the target segments in the test words differed along two dimensions: (1) their morphological function as part of a stem or root versus as part of an affix; and (2) their morphophonological recoverability. The spelling tests in both languages consisted of four conditions which differed in the number and type of cues for retrieving the correct spelling of homophonous graphemes. The cues were of two types: morphological cues, which offer spellers clues to the correct spelling through consistent orthography/morphology mapping regularities; and morphophonological cues, which offer spellers clues to the correct spelling through the manipulation of orthography/morphophonology conversion procedures.

A central finding of this study is the differential treatment of morphological cues by Dutch and Hebrew spelling learners. When faced with neutralized segments with and without morphological function, Hebrew-speaking children find morphology an enormously helpful tool. Dutch-speaking children, in contrast, do not find morphology a good cue provider. The impact of typology on the interface between spoken and written language is invoked as an explanation of the main findings.

In this note we discuss pMLU, a whole-word measure for phonological development that was proposed by Ingram (2002). Ingram's rules for calculating pMLU are analysed and we point at the crucial role of the level of transcription for making pMLU measurements comparable over different corpora. The main aim of the paper is an assessment of the reliability and the validity of pMLU. The assessment is accomplished using a computational tool for measuring pMLU on two large Dutch CHILDES corpora. We propose minimal sample sizes for reliable measurements relative to the stage of phonological development.

Children who acquire Dutch as their first language show a strong preference for using infinitival verb forms during the early stages of grammatical development. This exemplifies the ‘root infinitive’ (RI) phenomenon, which has played a significant role in recent discussions on the development of syntax. Most accounts proposed thus far invoke an immaturity of the child's grammatical competence. We explore the possibility that the early predominance of infinitival forms is related to patterns in the language input. We analysed a corpus of utterances addressed by two Dutch-speaking mothers to their two- to three-year old sons. Root infinitive utterances amounted to 10%, and auxiliary-plus infinitive main verb constructions, which in terms of word order are maximally similar to RIs, constituted 30% of all verb-containing utterances. These figures render an account in terms of exposure to utterance structures unlikely. There is a moderate (but significant) correlation between frequency of occurrence of individual verb forms in the input and age of acquisition. However, infinitive verb forms are often acquired earlier than their input frequency would predict, and this may be related to an overall increased salience, due to their systematic appearance in sentence-final position and their relatively high conceptual transparency as compared to finite verbs.