•Productions are primarily CV sequences, but now the reduplicative nature of the utterances is no longer present and a variety of consonants and vowels can co-occur (e.g. bawidu).

• Consonantal repertoire also increases substantially.

Variegated Babbling cont.

•Presence of adult-like intonation patterns.

• Locke (1983) examined the results of more than a dozen babbling studies and found that although there was a fairly wide range of consonants produced during this stage, their distribution varied.

Variegated Babbling cont.

The frequently occurring sounds included primarily stops, nasals, and glides (p,b,t,d,k,g,m, n,w,j,h,s) - whereas the infrequent sounds were mostly fricatives (except /s/), affricates and liquids (f,v,th,th,z,sh voiced sh, affricates, l,r,ng).

Variegated Babbling cont.

Although the variety of sounds increases during this stage, it must be kept in mind that certain sound classes occur with much greater frequency than other classes.

Variegated Babbling cont.

Data from three studies of English-learning infants ages 11 months - 1 year revealed that a set of 12 phones accounted for 92-97% of the consonants, whereas another 12 phones accounted for only 3-6% of the consonantal sounds.

•Short time span between the end of variegated babbling to the acquisition of the very first words!

• Although segments (phonemes) are similar from babbling to first words, there is a lot of individual variation!

Transition to First Words

•Formation of adult-like syllables with regular consonant and vowel-like segments.

• Incorporation of several different vocoids and contoids into the same production unit - both prepare children for production of first words.

Vihman (1986) study

•Studied children with 0, 4, and 15 words and made these distinctions:

–large diversity existed between phonetic tendencies, consonant inventories and word selection

– neither liquids nor consonant clusters appeared to any significant degree

–Eight of 10 children utilized voiced stops in babbling but not in words; /g/ was most prominent example.

– Labial sounds were most frequent

– all children showed preference for short vocalizations, especially monosyllables.

•Suprasegmentals - intonation continues; parent tries to "interpret"

First 50 Words

•Linguistic phase begins - first meaningful words

• Most define first word as a relatively stable phonetic form which is produced consistently by the child in a particular context.

• Example: ba for "ball" vs. dodo for "ball"

•Children often invent words (seem to have meaning for them but without a recognizable adult model). Sometimes referred to as protowords; vocables and quasi-words.

First 50 word stage

•Time from first meaningful utterance at approximately 1 year of age to approximately 18 months (begin to put two "words" together).

• Large difference between productional and perceptual capabilities of the child.

–E.g. say 50; understand 200

•This stage is heavily influenced by individual words child acquires.

• Perceptual, motor and cognitive growth all play critical roles in this stage of language acquisition.

•Factors that predominate:

–phonetic variability

– limitation of occurring syllable structures and sound segments.

•Stable forms vs. unstable forms

• Syllable shapes that are most common:

–CV, VC, CVC

•Common consonants include: labials (/p/ and /m/); followed by /t/ and later /k/: fricatives are present only after the respective homorganic stops have been acquired; first vowel is /a/, followed by /u/ and/or "ee".

Suprasegmentals

•Prosodic variations

• Pitch variations for different objects

• Intonation patterns may signal requesting, calling or demanding.

Preschool Child

•Phonology of child from 18 months to beginning of sixth year.

• Largest growth.

• Vocabulary increases substantially - 8000 words

• Have questions, negatives, dependent clauses and compound sentences.

Segmental development

•Review handout - studies completed earlier.

• Studies have problems:

–one word response

– choice of pictures/words affects sounds

– theoretical issue (speech sounds vs. phonology)

•Distinctive feature theory - (Jakobson, Fant, and Halle (1952) and Jakobson and Halle (1956)

• Distinctive features - an articulatory or acoustic parameter whose presence or absence defines a phoneme.

Distinctive Features cont.

•Goals -

1. To design one set of features to describe all possible phonemes in a language.

2. To design a purely binary feature system in which the plus or minus value of each feature could be applied to any sound, and

3. To devise the smallest number of features to accomplish goals 1 and 2.

Distinctive Features cont.

1. A binary system may be appropriate for a model of the language, but it may not be useful in describing what speakers do.

2. Too many researchers with too many different systems.

3. Often tells you what's not there vs. what is!

Definitions of Features Used by Chomsky and Halle (1968)

•Review handout
 
 

Distinctive Feature Theory