Chapter 5

Infant Speech Perception

Infants learning language must be able to segment the speech they hear into meaningful phrases and words

Speech perception ability

the ability to devote attention to the prosodic and phonetic regularities of speech, develops greatly over the first year

Frequency

pitch of sounds

Duration

length of sounds

Intensity

loudness of sounds

Stress

prominence placed on certain syllables of multi-syllabic

Intonation

prominence placed on certain syllables, applies to entire phrases and sentences

Prosodic characteristics

Frequency, Duration, Intensity

Phonetic details of speech

Phonemes (speech sounds); combinations of phonemes

Detecting Non-Native Phonetic Differences

ability to notice fine phonetic detail not limited to one's native language

Phonotactic regularities

permissible combinations of phonemes in one's native language

Allophones

variations of sounds in the same category

Voice onset time

interval between the release of a stop consonant (e.g., p, b, t, d) and the onset of vocal cord vibrations

Category Formation

ability to form categories, or to group items and events according to the perceptual and conceptual features they share is crucial for language development

Category formation is hierarchial

Superordinate, Subordinate, Basic

Superordinate level (Category Formation)

uppermost level in a category hierarchy, most general concept in a particular category, among the later words children acquire e.g. mammal

Subordinate level (Category Formation)

lowermost level in category hierarchy, specific concepts in a category e.g. poodle

Basic Level (Category Formation)

center of a category hierarchy, general concepts in a category e.g. dog

Reflexive sounds

very first kinds of sounds infants produce (Sounds of discomfort and distress; negative sounds produced during feeding)

Marginal babbling

short strings of consonant-like and vowel-like sounds; emerge as infants gain control of their articulation

Reduplicated

repeating consonant and vowel pairs (ma ma ma ma)

Non-reduplicated or variegated

non-repeating consonant and vowel combinations (da ma goo ga) - about 9 months

Infant-directed Speech

also called mothers or baby talk; speech we use in communicative situations with young language learners

Paralinguistic characteristics

the manner of speech in addition to the linguistic information: High overall pitch, exaggerated pitch contours, slower rate varied loudness

Nonlinguistic

exaggerated facial expressions, lots of gestures

Syntactic characteristics

smaller mean length of utterance (MLU), few subordinate clauses, more content words, fewer function words

Semantic characteristics

simple vocabulary

Discourse features

greater use of repetition, more questions than-adult-directed speech

Vygotsky (Joint reference and attention)

language development is a dynamic process that occurs within children's ZPD as they engage with more advanced peers and adults

3 major developmental phases with respect to joint reference and attention

1) Emergence to social partners
2) Emergence and coordination of joint attention
3) Transition to language

Joint attention

simultaneous engagement of two or more individuals in mental focus on a single object of focus

Supported joint engagement

techniques such as speaking with an animated voice or showing an infant novel objects

Intersubjective awareness

the recognition of when one shares a mental focus on some external object or action with another person

Intentional communication

the infants' attempts to deliberately communicate with others

Indicators of intentionality include

a) Infants alternates eye gaze between an object and a communicative partner
b) Infants use ritualized gestures, such as pointing
c) Infant persists toward goals by repeating or modifying their gestures when communicative attempts fail

Imperative pointing [protoimperitive]

requests to adults to retrieve objects, around 10 mos

Declarative pointing [protodeclarative]

social process between an infant and an adult (call adult's attention to objects, and to comment on object)

Key indicators of caregiver responsiveness

waiting and listening, following the child's lead, joining in and playing, being face to face, using a variety or questions and labels, encouraging turn taking, expanding and extending

3 rule-governed domains

content, form, and use

Content

words we use and meanings behind them (vocabulary system, lexicon)

Form

how we arrange words, sentences, and sounds to convey content

Use

language pragmatics, or how we use language in interactions with others in order to express personal and social needs

Language Content

Produce first true word at 12 mos. on average (Usually refer to salient people and objects in infants' everyday lives)

3 criteria for a true word

Clear intention and purpose
Recognizable pronunciation
Used consistently and generalized beyond the original context to all appropriate exemplars

Language Form

when infants begin to use true words, they generally utter these words in isolation for several months before they begin to combine words to make short phrases; generally have 35-50 words first

Language Use

communicate intentionally (starts by 8 months of age) by using a variety of pre-verbal language functions

pre-verbal language functions

attention seeking to self; attention seeking to events, objects, or other people; requesting objects; requesting actions; requesting information; greeting; transferring; protesting/rejecting; responding/acknowledging; informing

Receptive language

describes the language that infants comprehend

Expressive language

language that infants produce spontaneously, without imitating another's verbalizations

Norm referenced measures of language

MacArthur-Bates Communicative Development Inventory

Expressive language learners

use language primarily for social exchanges (Express their needs and describe their feelings as they interact with others; "Hi" and "bye-bye

Referential language learners

use language primarily to refer to people and objects (Enjoy labeling things; early vocabularies contain a large proportion of objects labels, "ball," "doggie," and "juice

Late talkers and early talkers

Extreme cases in lexical development at both ends of the range

Late Talkers

Children who exhibit delays in their expressive language development; Many are able to recover to normal language levels by age 3 or 4 but they may still exhibit delays in subtle aspects of language development

Early Talkers

Ahead of their peers in expressive language use; Between the ages of 11 and 21 months of age who are in the top percent for vocabulary production for their age on the MacArthur CDI

Habituating

presenting the same stimulus repeatedly to an infant until attention to the stimulus decreases

Dishabituation

infant's renewed interest in a stimulus

Habituation - Dishabituation Tasks (preset criteria)

Used to determine whether infants detect differences in pre-linguistic and linguistic stimuli and to determine how infants organize these stimuli categorically

Object exploration

infant manipulates objects for a specified period of time

Salience trial

measure whether the infant has an priori preference for one of the objects over the other object

Training phase

experimenter attempts to teach the infant the name of a novel object

Test trials

determine whether the infant has mapped the object name to the correct object