Margaret Kehoe

Voice onset time in bilingual German-Spanish children

This study examines the acquisition of the voicing contrast in German-Spanish bilingual children, on the basis of the acoustic measurement of Voice Onset Time (VOT). VOT in four bilingual children (aged 2;0–3;0) was measured and compared to VOT in three monolingual German children (aged 1;9–2;6), and to previous literature findings in Spanish. All measurements were based on word-initial stops extracted from naturalistic speech recordings. Results revealed that the bilingual children displayed three different patterns of VOT development: 1. Delay in the phonetic realization of voicing: two bilingual children did not acquire long lag stops in German during the testing period; 2. Transfer of voicing features: one child produced German voiced stops with lead voicing and Spanish voiceless stops with long lag voicing; and 3. No cross-language influence in the phonetic realization of voicing. The relevance of the findings for cross-linguistic interaction in bilingual phonetic/phonological development is discussed.

The Acquisition of Prosodic Structure: An Investigation of Current Accounts of Children's Prosodic Development.

This article examines four different approaches to prosodic acquisition: Gerkens S(W) production template; Fikkerts and Archibalds theories of stress acquisition, and Demuth and Fees prosodic hierarchy account. The predictions of prosodic circumscription, template mapping, and development according to the stages of the prosodic hierarchy are evaluated using a database of English-speaking childrens multisyllabic word productions. The results show that current approaches are unable to account for robust findings in the data such as the increased preservation of final over nonfinal unstressed syllables, segmental and prominence effects on truncation rate, and the relative infrequency of epenthesis and stress error patterns. Findings reveal a complex interaction between prominence, edge-based factors, and segmental effects in phonological development. The discussion explores how these findings may be accounted for within a constraint-based theoretical framework. *

Development of syllable structure in English-speaking children with particular reference to rhymes

This study investigates acquisition of the rhyme using cross-sectional and longitudinal data from 14 English-speaking children (aged 1;3-2;0). It focuses on 4 questions pertaining to rhyme development, which are motivated from current theories of prosodic acquisition: 1. Do children make vowel length errors in early acquisition?; 2. Do children acquire coda consonants before they learn the vowel length contrast?; 3. What consonants are first acquired as codas?; and 4. Is there a size constraint such that childrens productions are minimally and maximally bimoraic? The results indicate that the percentage of vowel length errors across all children was low irrespective of the percentage of codas produced. In particular, two children produced very few coda consonants and made few vowel length errors, suggesting that mastery of vowel length was not secondary to coda acquisition. With respect to coda segments, children produced voiceless obstruents as codas before sonorants supporting generally the claim that obstruents emerge before sonorants in coda position. Children produced coda consonants more frequently after short than long vowels consistent with a bimoraic size constraint in syllable development. The paper concludes by comparing the English findings with cross-linguistic work on vowel length acquisition.

Developing Vowel Systems as a Window to Bilingual Phonology.

This study examines the vowel systems of German-Spanish bilingual children in order to determine whether there is interaction between the two language systems. German has a larger vowel inventory than Spanish and also contains an opposition between long and short vowels. Given the differences in the vowel systems, which point to a more marked system in the case of German, two predictions are considered: (a) bilingual children will acquire the vowel length contrast in their German productions later than monolingual German-speaking children; and (b) bilingual children will acquire Spanish vowels similarly to monolingual children. In the German analysis, monosyllabic and disyllabic trochaic words were transcribed and acoustically analyzed. In the Spanish analysis, monosyllabic, disyllabic, and trisyllabic words were transcribed and a perceptual judgment was made as to whether the vowel production was a possible allophonic variant of the target vowel. The results confirmed both predictions. Bilingual children were delayed relaof the target vowel. The results confirmed both predictions. Bilingual children were delayed relative to monolingual children in the acquisition of the German vowel length contrast and displayed similar performance to monolingual children in the production of Spanish vowels. In the conclusion, the relevance of the findings to bilingual acquisition and to the acquisition of vowel length representation in childrens grammars is discussed.

Truncation Without Shape Constraints: The Latter Stages of Prosodic Acquisition.

This article evaluates the claim of uniform size and shape restrictions in prosodic development using a cross-sectional database of English-speaking childrens multi-syllabic word productions. Several of the youngest children in the study were limited by a bisyllabic output constraint, consistent with 1 stress-foot, and one of the oldest children produced output forms, consistent with 2 stress-feet, suggesting that uniform shape may occur at the earliest stages of prosodic development and on an individual basis for certain children. In the majority of cases, however, input-output correspondence between stressed and word-final syllables played the greatest role in explaining output patterns. Consequently, the article explores optimality accounts of truncation that do not assume a size restriction. Childrens increasing faithfulness to unstressed syllables can be explained by different constraint rankings that relate to edge alignment, syllable structure, and foot structure.

Support for metrical stress theory in stress acquisition

This study provides a detailed analysis of stress errors in English-speaking childrens word productions to determine whether the patterns of errors are consistent with the theoretical notions of metrical phonology. Children (aged 22–34 months) produced three-syllable novel and real words which varied according to metrical pattern. Results revealed three general stages in stress acquisition and support for metrical parameters, such as quantity-sensitivity, extrametricality, and main stress. Findings are compared with a recent analysis of stress development in Dutch-speaking children, based on a parametric metrical framework.

Stress error patterns in English-speaking children's word productions

This study examined the patterns of stress errors in English-speaking children’s productions of multisyllabic words to determine whether they were consistent with the rule-based acquisition of stress. Children (aged 22-34 months) produced three-syllable novel and real words and four-syllable real words which varied across stress pattern. Children’s productions were examined acoustically and perceptually. Results indicated significantly greater numbers of stress errors in SWS words and a tendency for greater numbers of stress errors in SWSW words, findings consistent with the increased association of stress errors with exceptional forms. Additional findings indicated that stress errors were more frequent in imitated compared to spontaneous productions, and that stress errors may be associated with articulatory and phonetic-control factors. The relevance of these findings to disordered populations is explored in the discussion.

The structure of branching onsets and rising diphthongs: evidence from the acquisition of French and Spanish

Abstract Consonant-glide-vowel (CGV) sequences are represented differently across languages. In some languages, the CG sequence is represented as a branching onset; in other languages, the GV sequence is represented as a rising diphthong. Given variable syllabification across languages, this study examines how young children represent CGV sequences. In particular, we evaluate Roses (2000) proposal, based on French acquisition data, that CGV sequences are initially represented as rising diphthongs. To do this, we examined childrens acquisition of CGV sequences in cross-sectional data from 14 French-speaking children (aged 1;10–2;10 years) and longitudinal data from five Spanish-speaking children (aged 1;3–3;0 years). Across several different measures (order of acquisition, style of acquisition, positional faithfulness, error patterns), childrens production of rising diphthongs and branching onsets patterned similarly. The results suggest that at least for these children, CGV sequences are represented as branching onsets during the early stages of acquisition.

The acquisition of nuclei: a longitudinal analysis of phonological vowel length in three German-speaking children

Studies of vowel length acquisition indicate an initial stage in which phonological vowel length is random followed by a stage in which either long vowels (without codas) or short vowels and codas are produced. To determine whether this sequence of acquisition applies to a group of German-speaking children (three children aged 1;3-2;6), monosyllabic and disyllabic words were transcribed and acoustically analysed. The results did not support a stage in which vowel length was totally random. At the first time period (onset of word production to 1;7), one childs monosyllabic productions were governed by a bipositional constraint such that either long vowels, or short vowels and codas were produced. At the second (1;10 to 2;0) and third time periods (2;3 to 2;6), all three children produced target long vowels significantly longer than target short vowels. Transcription results indicated that children experienced more difficulty producing target long than short vowels. In the discussion, the findings are interpreted in terms of the representation of vowel length in childrens grammars.

Intervocalic consonants in the acquisition of German: onsets, codas or something else?

This study examines the behaviour of five phonemes /f, P, ts, k, l/ in word-initial, word-final, and intervocalic positions in the productions of five German-speaking children (age 1;3 to 3;3 years) in order to determine the patterning of those intervocalic consonants - do they behave more like onsets or codas? The study also contrasts the behaviour of intervocalic consonants after short versus long vowels in view of the stance taken in the theoretical literature that intervocalic consonants after short vowels are ambisyllabic but not after long vowels. Findings show that out of 25 conditions (5 phonemes 2 5 children), nine yield support for the patterning of intervocalic consonants as codas, two as onsets, and five as unique (neither coda nor onset). Three conditions yield support for the dual patterning of intervocalic consonants. In all other conditions, there was insufficient information to support their patterning with codas or with onsets. Results provide minimal support for different patterns of intervocalic consonants after short and long vowels; however, the lengthening and insertion of consonants after short vowels suggest that children are aware of the different phonological roles of intervocalic consonants after short and long vowels.