NOVA Comprehensive Perspectives on Child Speech Development and Disorders Chapter 5 Transitions to First Words Anna Sosa 1

NOVA Comprehensive Perspectives on Child Speech Development and Disorders Introduction By their first birthdays, children begin to produce recognizable words By their second birthdays, children have an expressive vocabulary of ~ 300 words The “first words period” is generally defined as the time from the first word to a vocabulary of ~ 50 words (usually attained at ~ 18 months) 2

NOVA Comprehensive Perspectives on Child Speech Development and Disorders Defining True Words True word – Stable semantic referent – Relatively stable phonetic form – Similar to the adult phonetic form Protoword – Semantic referent can be context dependent – Can have a stable phonetic form and can be accompanied by gestures – Not similar to the adult phonetic form – Example: [mamamam] while using a reaching gesture toward a desired object with opening and closing of the fingers may be interpreted to mean “give me” or “I want that” 3

NOVA Comprehensive Perspectives on Child Speech Development and Disorders Relationship Between Babble and First Words Overlap between babble and words – Babble and first words Co-exist for a few months Have similar types of segments (stops, nasals, glides) Have similar syllable shapes (predominantly CV) – Feedback loop: Auditory and kinesthetic input during production – Another type of feedback: Social feedback Caregivers reinforce CV babble by interpreting it as real words – Child: [dædæ]. Caregiver: “You said ‘Daddy’!” 4

NOVA Comprehensive Perspectives on Child Speech Development and Disorders Greatly variable among children but there are trends: – Manner classes Stops Nasals Glides (no fricatives, affricates, liquids) – Syllable structure CV (“bye”) CVC (“mom”) CVCV (“baby”) – Initial consonants more frequent than final consonants – Initial consonants tend to be voiced, final consonants tend to be voiceless 5

NOVA Comprehensive Perspectives on Child Speech Development and Disorders Sidebar 5.1 Earliest Words. The first ten words acquired by English-speaking children according to CDI normative data daddy mommy bye ball hi dog no baby kitty book 6

NOVA Comprehensive Perspectives on Child Speech Development and Disorders How do children communicate effectively with such limited inventories and syllable shapes? – They modify the adult forms ([da]/dogl) – They choose to talk about words that fit their limited segmental and syllabic inventory (lexical selection) Young children preferentially produce words that start with /b/ but not /p/; later, they begin to choose words with later-developing consonants (Stoel-Gammon, 1998; Stoel-Gammon & Peter, 2008) Similar trends are found in languages other than English 7

NOVA Comprehensive Perspectives on Child Speech Development and Disorders Preferred Patterns in Individual Children – There is great variability among children – Vocal motor schemes in individual children Preference for sibilants in initial position (Ferguson & Farwell, 1975) Velar stops in final position (Stoel-Gammon & Cooper, 1984) 8

NOVA Comprehensive Perspectives on Child Speech Development and Disorders An Emerging Phonological System The word as the minimal unit of production – Unclear whether young children have a mental representation of the whole adult word form or if they just store a chunked reduced set of sounds – but probably not individual speech sounds yet – Within a given child, productions can be highly variable (fuzzy representation) Inter-word ([tæt]/cat but [kʌm]/come) Intra-word Often, no consistent phonological pattern (“phonological processes”) can be observed in the differences between the child and adult forms during the first-words period 9

NOVA Comprehensive Perspectives on Child Speech Development and Disorders Other examples for intra-word variability from two children, age 24 months (Sosa & Stoel-Gammon, in press, cited with permission) – “juice”: [dus, dʊst, ʤʊs, dʊʃ, ʤʊʃ] – “frog”: [bwʌk, wʌk, fwʌt, fwʌ, fwʌk] 10 5V1 Play session with a boy, age 20 months Sidebar 5.2 Intra-Word Variability

NOVA Comprehensive Perspectives on Child Speech Development and Disorders The Word as the Minimal Unit of Production – Articulatory templates Nasal template, example from Estonian.. [næŋ], [nɪŋ], and [nɪn] for target /kiŋ/ meaning “shoe” and [nən] for adult target /rind/ meaning “breast” Sibilant template, example from English: (C) + V + ʃ – [ʊʃ] for both “fish” and “vest” 11

NOVA Comprehensive Perspectives on Child Speech Development and Disorders 12 Sidebar 5.3 Perception vs. Production Some aspects of speech perception and production in early childhood make for a puzzling mix of seeming contradictions. Based on characteristics of early speech production, children are often thought to lack phonetic detail in their phonological representations and are described as using more holistic or “whole- word” representations. Conversely, infants by 4 months of age have demonstrated remarkable sensitivity to subtle phonetic distinctions (e.g., Eimas, Siqueland, Jusczyk & Vigorito, 1971) and older children who produce errors on certain speech sounds often reject an adult’s production of a word that demonstrates the same error, suggesting that they are able to perceive the mistake when produced by someone else. Due to these inconsistencies, the debate regarding the nature of young children’s phonological representations persists.

NOVA Comprehensive Perspectives on Child Speech Development and Disorders Transitions to a Phonemic System When do children transition from a fuzzy awareness of word forms to an awareness of the individual speech sounds within words? Several ideas have been proposed: – At the end of the first-words period when the child has 50 words (Vihman, 1996) – Not complete until 7 or 8 years Charles-Luce & Luce, 1990; Garlock, Walley & Metsala, 2000 All agree that the process of phonemic awareness requires a growing vocabulary. Why might that be? 13

NOVA Comprehensive Perspectives on Child Speech Development and Disorders Connections The present chapter focuses on the transition from babble to words in typically developing children Chapter 6 provides an overview of speech development from the early words stage to school-age Chapters 17, 18, and 19 focus on speech development in special populations with a variety disorders such as sensory, structural, and developmental To diagnose speech disorders in very young children, no norm-referenced tools are available but the Preschool Language Scale – 4 th Edition (PLS-4) includes two criterion-referenced items that probe early speech development 14

NOVA Comprehensive Perspectives on Child Speech Development and Disorders Concluding Remarks This chapter retraces the work from the 1970s onward that showed many continuities between prespeech and speech development It also provides evidence to show that young children’s representations of words may be more global and less segmentally specified than those of adults Much work needs to be done to investigate speech development in young typical children and to identify early signs of disordered speech development 15