Phonological Development

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Phonological Development

• Ages and Stages

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Discussion Outline

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

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Discussion Outline (continued)

• Types of Analyses
• Independent Relational
• Profile of Typical 2 year old
• Who are Late Talkers?
• Profiles of Late Talkers
• Rescorla Ratner
• Williams Elbert
• Develop a Protocol for Late Talkers

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4 Stages of Development

• 1. Prelinguistic (0 - 1 year)
• reflexive vocalizations
• cooing
• vocal play
• babbling
• variegated babbling

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2. First Words (1 - 1.6)

• Whole-word strategy
• Unanalyzed wholes
• Progressive idioms

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3. Phonemic Development (1.6 - 4)

• Rule-governed strategy
• 50 word vocabulary

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4. Stabilization

• Acquisition of later sounds

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Developmental Norms

• Segmental acquisition studies
• Phonological process norms

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Theories of Phonological Acquisition

• Universalist-Linguistic
• Unfolding of abilities (linear progression)
• passive learner
• universal order of acq (all children develop in
  same way)

• Cognitive
• non-linear development
• acti ve learner
• individual differences

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Theories of Phonological Acquisition

• Universalist-Linguistic
• learning to pronounce is lower level skill-gt
  developmental sequence
• related to/constrained by anatomical/physio
  characteristics of human auditory/artic tracts
• phonemes and individual sounds are the units of
  acquisition

• 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

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Summary of Cognitive Model of Phonological
Acquisition

• 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

• Evidence
• progressive idioms
• experimentation
• hypothesis formation

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Summary of Cognitive Model of Phonological
Acquisition

• Process of Acquisition
• Childs categories not necessarily same as
  adults
• Recognizes new and relevant information
• Creates new rules

• Evidence
• Overgeneralization/ Regression
• Changes Hypotheses
• Hypothesis Formation

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3 Components of Early Phonological Development
(Stoel-Gammon, 1991)

• 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

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3 Components (continued)

• 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

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3 Components (continued)

• 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

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Differences in Assessing Early vs Later
Linguistic Behaviors (Stoel-Gammon, 1991)

• Given the tremendous individual variation in
  early development (babbling -gtfirst words-gtword
  combinations), MUST use broad evaluations rather
  than focus on indidividual phonemes
• Normal development at this age cant be
  determined by comparing childs performance with
  set of norms like those used for older children

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Stoel-Gammon (1991) Continued

• Must include size and nature of phonetic
  inventory, correct productions, error types, and
  overall intelligibility (INDEPENDENT RELATIONAL
  ANALYSES)
• ALSO
• age of onset of meaningful speech
• lexicon size

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Two Types of Analyses Used in Assessing Younger
Children

• 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 childs pronunciation of word with adult
  form and identifies what is correct/ incorrect in
  relation to adult target
• PCC
• error patterns (phonological processes)

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Profile of Typical 2 Year Old (Stoel-Gammon, 1987)

• Syllable Structure
• Simple structure
• CV, CVC, CVCV, CVCVC
• Few or no clusters
• only WF

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Profile (continued)

• 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

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Profile (continued)

• Accuracy
• about 70 accuracy
• this suggests that children kept their vocabulary
  IN their phonology

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Who are Late Talkers?

• At 24 months, child has lt 50 word vocabulary
  AND/OR
• phonetic inventory with only 4-5 consonants and
  limited variety of vowels

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Phonetic Profiles of Toddlers with SLI-E
(Rescorla Ratner, 1996)

• 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

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Rescorla Ratner Conclusions

• Results suggest that non-grammatical (I.e.,
  phonetic) factors contribute to the development
  of expressive language deficits in toddlers
• 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

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A Prospective Longitudinal Study of Phonological
Development in Late Talkers (Williams Elbert,
2003)

• Independent Analyses
• Phonetic Inventory (WI/WF)
• Syllable Structure
• Preferences (frequency of occurrence) TOKEN
• Complexity (clusters)
• Diversity ( different syllable structures) TYPE

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Williams Elbert (continued)

• 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) gt
  1.0
• many-to-one correspondence (free variation) lt
  1.0
• Error Patterns
• MLU and Lexicon Size

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Phonological Delay Vs Phonological Deviance
(Williams Elbert, 2001)

• 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

• 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

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Phonological Delay Vs Phonological Deviance
(Williams Elbert, 2001)

• Delay
• Higher PCC (.56) at 31-33 months
• Lower variability (1.2) at 31-33 months
• Typical errors
• Fast rate of resolution

• Deviance
• Lower PCC (.34) at 40-41 months
• Greater variability (1.74) at 40-41 months
• Atypical errors
• Slow or no resolution

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Conclusions (Williams Elbert, 2003)

• Quantitative aspects of phonological and language
  skills (inventory size, lexicon size, MLU) were
  NOT diagnostic markers for identifying DELAYED vs
  DEVIANT
• 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

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Develop a Protocol for Assessing Early Linguistic
Behaviors of Late Talkers

• How would you elicit the sample?
• How would you analyze the sample?
• Complete Analysis on Nicholas
• Go beyond analysis to synthesis/summary -gt 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 Elberts Red Flags