Phonological Development Ages and Stages Discussion Outline b

Phonological Development Ages and Stages

Discussion Outline b Normal Developmental Stages b Developmental Norms • segmental norms vs phonological processes b Theories of Phonological Acquisition • Cognitive Model of Phonological Acquisition b Components of Early Phonological Development b Differences in Assessing Early vs Later Phonological Abilities

Discussion Outline (continued) b Types of Analyses • Independent + Relational b Profile of Typical 2 year old b Who are Late Talkers? b Profiles of “Late Talkers” • Rescorla & Ratner • Williams & Elbert b Develop a Protocol for Late Talkers

4 Stages of Development b 1. • • • Prelinguistic (0 - 1 year) reflexive vocalizations cooing vocal play babbling variegated babbling

2. First Words (1 - 1. 6) b Whole-word strategy b Unanalyzed “wholes” b Progressive idioms

3. Phonemic Development (1. 6 - 4) b Rule-governed strategy b 50 word vocabulary

4. Stabilization b Acquisition of later sounds

Developmental Norms b Segmental acquisition studies b Phonological process norms

Theories of Phonological Acquisition b Universalist-Linguistic • Unfolding of abilities (linear progression) • passive learner • universal order of acq (all children develop in same way) b Cognitive • non-linear development • acti ve learner • individual differences

Theories of Phonological Acquisition b Universalist-Linguistic • learning to pronounce is lower level skill-> developmental sequence – related to/constrained by anatomical/physio characteristics of human auditory/artic tracts • phonemes and individual sounds are the units of acquisition b Cognitive • acquisition of phono is cognitive process in the way child: – – – a. forms categories b. recognizes patterns c. forms rules • processes of acquis – – – selectivity creativity hypothesis formation

Summary of Cognitive Model of Phonological Acquisition b Process of Acquisition • whole-word acquisition (unanalyzed) • recognizes similarities b/w classes of sounds and constructs rules for relating similar sounds and formulate rules • develops a rule and applies it to other related items b Evidence • progressive idioms • experimentation • hypothesis formation

Summary of Cognitive Model of Phonological Acquisition b Process of Acquisition • Child’s categories not necessarily same as adult’s • Recognizes new and relevant information b Evidence • Overgeneralization/ Regression • Changes Hypotheses • Creates new rules • Hypothesis Formation

3 Components of Early Phonological Development (Stoel-Gammon, 1991) b General Patterns of Development • at 24 mo, generally have expressive vocab of ~ 300 words • ~ 50% of what they say is understood by strangers • by 3 yrs, 75% intelligibile with vocal of ~ 1000 wds and MLU of 3. 1

3 Components (continued) b Individual Differences • Lot of variation among 2 year olds, but certain commonalities: – final inventory never greater than initial inventory – tendency for stops, nasals, glides before frics, liquids, affrics – front consonants appear before back consonants

3 Components (continued) b Atypical Development / RED FLAGS • numerous vowel errors • frequent initial consonant deletion • substitution of glottal stop of [h] for various consonants • deletion of final consonants at 3 years

Differences in Assessing Early vs Later Linguistic Behaviors (Stoel-Gammon, 1991) b Given the tremendous individual variation in early development (babbling ->first words->word combinations), MUST use broad evaluations rather than focus on indidividual phonemes b Normal development at this age can’t be determined by comparing child’s performance with set of norms like those used for older children

Stoel-Gammon (1991) Continued b Must include size and nature of phonetic inventory, correct productions, error types, and overall intelligibility (INDEPENDENT + RELATIONAL ANALYSES) b ALSO: • age of onset of meaningful speech • lexicon size

Two Types of Analyses Used in Assessing Younger Children b b Independent Analysis • focuses on the sound types and syllable structures produced by the child independent of the adult target – phonetic inventory (by WI/WF positions) – syllable structure Relational Analysis • compares child’s pronunciation of word with adult form and identifies what is correct/ incorrect in relation to adult target – PCC – error patterns (phonological processes)

Profile of Typical 2 Year Old (Stoel-Gammon, 1987) b Syllable Structure • Simple structure – CV, CVCV, CVCVC • Few or no clusters – only WF

Profile (continued) b Phonetic Inventory • Word-Initial Inventory – 9 -10 different sounds – stops, nasals, frics, glides • Word-Final Inventory – 5 -6 different sounds – primarily stops with some nasals, frics, liquids

Profile (continued) b Accuracy • about 70% accuracy • this suggests that children kept their vocabulary IN their phonology

Who are “Late Talkers”? b At 24 months, child has < 50 word vocabulary; AND/OR b phonetic inventory with only 4 -5 consonants and limited variety of vowels

Phonetic Profiles of Toddlers with SLI-E (Rescorla & Ratner, 1996) b Variables that distinguished SLI-E children from TD children at 24 -31 months included: • vocalization rate – SLI-E vocalized less – potentially perpetuate exp lang delay by losing opportunities for vocal practice • size of consonant inventory – SLI-E had restricted inventories (b, d, nasals, glides, h) • syllable shape preferences – SLI-E used V and CV shapes primarily

Rescorla & Ratner Conclusions b Results suggest that non-grammatical (I. e. , phonetic) factors contribute to the development of expressive language deficits in toddlers b Suggest a bidirectional association between child vocalization and maternal interaction • limited phonetic capacity interacts with caregivers’ interactions in a way that further reduces opportunities for exp lang learning and practice

A Prospective Longitudinal Study of Phonological Development in Late Talkers (Williams & Elbert, 2003) b Independent Analyses • Phonetic Inventory (WI/WF) • Syllable Structure – Preferences (frequency of occurrence) TOKEN – Complexity (clusters) – Diversity (# different syllable structures) TYPE

Williams & Elbert (continued) b Relational Analyses • PCC • Sound Variability (stability of sound system) – # diff cons attempted/# diff cons produced – – – • • no variability = 1. 0 one-to-many correspondence (phoneme collapse) = > 1. 0 many-to-one correspondence (free variation) = < 1. 0 Error Patterns MLU and Lexicon Size

Phonological Delay Vs Phonological Deviance (Williams & Elbert, 2001) b Delay • Larger inventories – 13 -15 WI; 8 -11 WF (at 32 months) • Greater syll diversity – 9. 2 different syllables at 22 -33 mo • More complex syll – 5. 4 complex syllables at 22 -33 months b Deviance • Limited inventories – 6 -9 WI; 1 -5 WF (at 32 months) • Limited syll diversity – 7. 5 different syllables at 30 -41 mo • Simple syll structures – 1. 1 complex syllables at 30 -41 months

Phonological Delay Vs Phonological Deviance (Williams & Elbert, 2001) b Delay b Deviance • Higher PCC (. 56) at 3133 months • Lower PCC (. 34) at 4041 months • Lower variability (1. 2) at 31 -33 months • Greater variability (1. 74) at 40 -41 months • Typical errors • Atypical errors • Fast rate of resolution • Slow or no resolution

Conclusions (Williams & Elbert, 2003) b Quantitative aspects of phonological and language skills (inventory size, lexicon size, MLU) were NOT diagnostic markers for identifying DELAYED vs DEVIANT b Instead, qualitative differences (greater variability and unusual sound errors) were identified markers of long-term delay • However, the extent of the delay was greater for the kids who did not catch up

Develop a Protocol for Assessing Early Linguistic Behaviors of Late Talkers b b How would you elicit the sample? How would you analyze the sample? Complete Analysis on Nicholas • Go beyond analysis to synthesis/summary -> what is significant? Diagnosis • Normal Vs Delayed Vs Deviant? • Compare results to Stoel-Gammon – a. Profile of typical 2 year old – b. Red flags • Compare results to Williams & Elbert’s Red Flags