Carol Stoel-Gammon

Patterns of early lexical and phonological development

This paper presents a detailed analysis of early lexical and phonological development in three children. The study covers the period from late babbling through the acquisition of 50 conventional words and focuses on: (1) the relationship between prelinguistic and linguistic vocalizations; (2) phonological development after the onset of speech; (3) patterns of lexical selection; (4) rate of lexical acquisition; and (5) use of invented words. The findings reveal that while the prelinguistic utterances of the children were similar, there was extensive inter-subject variation after the onset of meaningful speech, particularly in the segmental and syllabic forms of word productions, patterns of lexical selection, rate of lexical acquisition, and use of invented words.

Relationships between lexical and phonological development in young children

Our understanding of the relationships between lexical and phonological development has been enhanced in recent years by increased interest in this area from language scientists, psychologists and phonologists. This review article provides a summary of research, highlighting similarities and differences across studies. It is suggested that the research falls into two categories with different goals and different methodological approaches: (1) child-centered studies that examine the influences active in the prelinguistic and early-word period, emphasizing individual developmental patterns and the active role played by the child; and (2) studies inspired by research on word processing in adults; these focus on the effects of the phonological and lexical characteristics of the ambient language on underlying representations and word learning in children. The article concludes with suggestions for integrating the findings from the two approaches and for future research.

Phonological Skills of 2-Year-Olds.

Conversational speech samples from 33 2-year-olds were analyzed to determine the word and syllable shapes produced, the inventories of initial and final consonantal phones and the percentage of consonants correct. The findings provide a profile of the phonological skills of normally developing 2-year-olds which can be used to assess young children with possible phonological disorders.

Vowel systems of normally developing and phonologically disordered children

Available literature on the acquisition of vowels in normally developing and phonologically disordered subjects is reviewed and detailed case studies of the vowel productions of two phonologically disordered subjects are presented. The findings reveal parallels between the accuracy levels for disordered subjects and order of mastery in younger normal children. In both populations, corner vowels are produced accurately before non-corner vowels. Unstressed vowels were found to be problematic for children with phonological disorders.

A quantitative analysis of reduplicated and variegated babbling

A number of investigators have made reference to the stages of reduplicated and variegated babbling during the latter half of pre meaningful vocal development. Although these categories of utter ances are widely accepted, there is little quantitative data describing them. The present study investigated this issue by analysing the utter ances of 10 infants who were followed at approximately 4-month intervals from about 6-18 months of age. Although there was a period during which reduplicated utterances were found to occur somewhat more frequently than variegated productions, followed by a period of more frequent occurrence of variegated productions, both types co- occurred throughout the entire age range studied. Specific phonetic characteristics of these two types of vocalizations were also inves tigated to determine whether they provided any information about the development of articulatory motor control.

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. *

Phonological development in Down syndrome

This article provides an overview of the literature on phonological development in infants and children with Down syndrome. The review is divided into four major sections: the first summarizes studies of factors that may impede normal phonological development in this population: hearing loss and abnormalities of the middle ear; anatomical and physiological features of the speech mechanism; characteristics of input; and perceptual and encoding abilities. The second section examines prelinguistic vocal development and the links between babble and speech. The third section reviews literature on phonological acquisition after the onset of meaningful speech and briefly summarizes research on speech intelligibility in Down syndrome individuals. The fourth section discusses recommendations for intervention programs aimed at improving articulation and phonology in children with Down syndrome. MRDD Research Reviews 1997;3:300–306.

THE UNDERSPECIFICATION OF CORONALS: EVIDENCE FROM LANGUAGE ACQUISITION AND PERFORMANCE ERRORS

Publisher Summary Coronals often take part in phonological patterns that are different from those of other places of articulation. In many languages, coronals assimilate to other places of articulation even though velars and labials do not assimilate. Such behavior has been used to argue that coronals are not specified for place of articulation in underlying forms. This chapter discusses the underspecification of coronals, which is evident from language acquisition and performance errors. It explores error phenomena involving the interaction of coronals with other places of articulation. In English, [coronal] would be specified for obstruents and /n/ because place of articulation is contrastive. The only alveolars for which it would be underspecified are /l/ and /r/; as the only liquids in English are alveolars, their place of articulation is not contrastive.

Patterns of Intra-Word Phonological Variability during the Second Year of Life.

Phonological representation for adult speakers is generally assumed to include sub-lexical information at the level of the phoneme. Some have suggested, however, that young children operate with more holistic lexical representations. If young children use whole-word representation and adults employ phonemic representation, then a component of phonological development includes a transition from holistic to segmental storage of phonological information. The present study addresses the nature of this transition by investigating the prevalence and patterns of intra-word production variability during the first year of lexical acquisition (1;0-2;0). Longitudinal data from four typically developing children were analysed to determine variability at each age. Patterns of variability are discussed in relation to chronological age and productive vocabulary size. Results show high overall rates of variability, as well as a peak in variability corresponding to the onset of combinatorial speech, suggesting that phonological reorganization may commence somewhat later than previously thought.

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.