Phonetics & LinguisticsSpeech Sciences

Speech Developement

© Volker Dellwo (2003)

Child Language Acquisition Introduction

child language acquisition can be studied from different points of view:

Phonetic/phonologicaldevelopment

Grammatical development

Semantic development

Pragmatic development

How do we learn the sounds of the language by means of our organs of speech and hearing?

How do we learn the syntactic structure of a language?

How do we learn what words, phrases, and sentences mean?

How do we learn about the situational meaning of language?

SPEECH DEVELOPEMENT

Child Language Acquisition

two main different areas in speech development

speech production speech perception

analysis e.g. by:

• recording sound

• laryngography

• filming

• etc.

analysis e.g. by:

• sucking experiments

• head turning experiments

Focus of thislecture:

Introduction

strong methodological differencesin how we study these two areas:

Child Language Acquisition Speech Production

Fundamental point of interest: At what point does the child learn how to use the different functions of the organs of speech?

When does the child learn the use of...

... rhythm

... changes of pitch

etc.

sound segments: suprasegmental or prosodic features:

When does the child learn to produce...

... which sound?

... sounds in combination?

... words?

etc.

Child Language Acquisition Speech Production

Question:Are the first sounds produced by infants vowels or consonants?

Answer:

Question: When do children start producing their first word?

Answer:

Question: So what happens before?

Child Language Acquisition Speech Production

The first year in speech production

pre-babbling0-25 weeks

babbling25-50 weeks

basic biological noises

0-8 weeks

cooing8-20 weeks

vocal play20-30 weeks

melodic utterances9-18 months

Child Language Acquisition Speech Production

Stage I: Basic biological noises (0-8 weeks)1.) sounds directly reflect the baby's biological s tate and activities:

breathing, eating, excreting, sucking, swallowing, coughing, burping, etc.

���� rather consonant like sounds

2.) crying sounds:

Hunger cries, pain cries, discomfort cries, etc.

���� rather vowel like sounds

Early sounds are not language specific.

BUT

Rhythmical vocalisation, vocal folds are used to produce speech patterens which are fundamental characteristics of later speech.

back

Child Language Acquisition Speech Production

Stage II: Cooing (8-20 weeks)Vowel like sounds of rather indeterminate character with nasal qualityoften acompanied by a preceeding consonant like sound producedtowards the back of the vocal tract.

backTime (s)0 5.91206

0

5000

Child Language Acquisition Speech Production

Stage III: Vocal Play (20-30 weeks)- longer segments with higher pitch variation- higher absolute pitch- consonant + vowel like sequences

backTime (s)0 4.39314

0

5000

Child Language Acquisition Speech Production

Stage IV: Babbling (25-50 weeks)- smaller set of sounds repeating more often than in vocal play- highly reiterative [babababa, dadadada, gagaga]- no clear boundary between babbling and spoken language

backTime (s)

0 4.667030

5000

Child Language Acquisition Speech Production

Stage IV: Melodic Utterance (25-50 weeks)- closest imitation of real speech with no meaning- high use of different sound segments (consonants & vowels)- suprasegmental features are already being imitated

backTime (s)

0 2.911020

5000

Child Language Acquisition Speech Production

use of different places of articulation according to ag e

age

0-3 3-6 6-9 9-12 12-150

100

velaralveolar

labial

-up to 6 months velar soundsare predominant

-after six months alveolar soundsare predominant

-labial sounds are never pre-dominant

children seem to have thecapability to produce the wordsof the language long beforethese sounds are used in speech.

Child Language Acquisition Further development

What happens next?(i.e., after 18 months)

phonological development

(semantic developmentpragmatic development)

grammatical development

Child Language Acquisition Further development

Question:What comes earlier: production or perception of sounds?

Does a child first have to learn how to produce a sound firstbefore it is able to perceive it?Or can children distinguish sounds they actually are not ableto produce themselves?

Phonological development: acquisition of the sound system of a language

Child Language Acquisition Further development

Answer:The 'fis' phenomenon (a true story!)

A child called his inflated fish a /fis/. In imitation of the child's pronunciation,the observer said: 'This is your fis?' 'No,' said the child, 'my fis.' He continuedto reject the adults imitation until he was told, 'That is your fish.' 'Yes' he said, 'my fis.'

Phonological development: acquisition of the sound system of a language

� Children know far more about the phonology of their language than theirown pronunciation suggests!

� Children actually know about the sounds of their language long time before they can produce them fluently.

Child Language Acquisition Further development

The emergence of consonants:

n2

2,4

3,8

3,0

3,4

4,0

2,8

+ 4

mph

w

s

fN

bgt

k

jd

lr

StSdZ

v

zZ

D T

Child Language Acquisition Further development

replacements acording to place of articulation:e.g.: velar consonants tend to be replace by alveolar consonants ('don' for 'gone')

replacements acording to manner of articulation:e.g.: fricatives tend to be replaced by stops ('tee' for 'see')

Avoidance of consonant clusters (i.e.: 'kai' for 'sky') and consonants at the end of words (i.e.: 'ha' for 'hat').

The emergence of consonants:

Child Language Acquisition Further development

pitch of vowels: Pitch of vowels of young children is much higher:

infants : from 400 to 800 Hzadult females : from 150 to 350 Hzadult males : from 75 to 200 Hz

formant frequencies of vowels:Formant frequencies of children tend to be higher because of a shortervocal tract which has higher resonance frequencies.

boys and girls:There is no difference between male and female infants according to pitch and formants as it would be with grown ups.

The emergence of vowels:

Child Language Acquisition Further development

• between 12 & 18 months: one word utterances

• from 18 months: two word sentences

• from 2 years onwards: three and more word sentences

Grammatical development