Module 6 Phonological Development The Emergence of Speech.

Module 6Phonological Development

The Emergence of Speech

Key Concepts for Understanding•Phonological awareness/knowledge•Phonological boundaries•Organs of articulation•Pre-linguistic sounds•Infant directed speech/motherese•Phonetic features•Models of phonological development

Points for Discussion •The acquisition of phonology consists of learning to distinguish and produce the sound patterns of the adult language.

•It is also consists of learning and coming to mentally represent the structure underlying those sound patterns.

Pre-Linguistic Speech and Development of Speech Perception

•It was thought that babies were deaf at birth and that basic sensory abilities matures only later.

•Infants’ hearing is not quite as sensitive as adults but it is certainly adequate for hearing speech from the time infants are born (Kuhl, 1987).

•The auditory system is already functioning in the fetus even before birth.

On auditory system •The fetus will move in utero in response to external sound (Kuhl, 1987).

•On mothers’ voices based on the studies conducted by DeCasper and Fifer (1980) and DeCasper and Spence (1986)

•Fetuses seem not only to hear but to remember what they hear. One group of researchers played recordings of their mother’s and stranger’s voice to 38-week old fetuses

•DeCasper and Spence (1986) had pregnant women read a particular passage aloud every day during the last 6 weeks of their pregnancy.

•Infants can discriminate essentially all the sound contrasts languages use.

•The High-Amplitude Sucking (HAS) Technique makes use of three characteristics of babies: (1) Babies like to hear sounds, (2) babies lose interest in a sound when it is presented repeatedly, and (3) babies who have lost interest in a previously repeated sound will become interested if a new sound is presented.

•In the HAS procedure, interest is measured by the baby’s willingness to “work” to hear the sound played over a speaker. (Hoff, 2009).

The Head-Turn Technique

•It is typically used with babies between 5 and 12 months old. This procedure makes use of the fact that babies are interested in a moving toy, such as a monkey that claps cymbals together. Using the presentation of the moving toy as a reward, babies can be trained to turn their heads when they hear a change in a sound being presented.

Infants’ Discrimination of Speech Sounds•Infants can discriminate essentially all the sound contrasts languages use. For example, infants as young as 4 weeks old can discriminate vowel contrasts such as /u/ versus /I/ and /I/ versus /a/(Trehub, 1973) and consonants contrasts such as /p/ versus /b/ and /d/ versus /g/ (Aslin, Jusczyk, & Pisoni, 1998).

Infant-Directed Speech In many cultures, adults use a particular way of speaking with babies (Fernald et al., 1986). This style of speech is sufficiently different from the way adults talk to other adults that it has been given its own name ---motherese or infant-directed speech or child-directed speech (Newport, Gleitman & Gleitman, 1977).

Please see page 6.

Infant-Directed Speech as a Universal Signal-System

•-assumed to be a special speech register for talking to infants

•A substantial body of research has investigated how infants respond to infant-directed speech and what infants might learn from it. Several findings make the case that infants prefer to hear infant-directed over adult-directed speech (Hoff, 2009).

•Anne Fernald (1985) recorded 10 different adult women talking to their 4-month-old infants and to an adult.

•Experiments conducted:•1. infant-directed speech tape to 4-month-

old infants

•Result: •The infants chose to hear infant-directed

speech more frequently than they chose to hear the adult-directed speech.

• Please see page 6.

When talking to babies, adults use higher-pitched voice, a wider range of pitches, longer pauses and shorter phrases (Fernald et al., 1989).

•For 4-month-old babies, it seems to be exaggerated pitch contours. Fernald and Kuhl (1987) found that the4-month-olds preferred to hear infant-directed speech when everything but the melody had been filtered out of the speech signal.

• Please see page 6.

Bold colors and black on white patterns (study conducted by Vihman, 1996)•It seems that mothers naturally produce

sounds that interest babies (Hoff, 2009).

• Please see pages4 (3).

•The Role of Infant-Directed Speech

• The infant-directed speech might also support language acquisition by providing particularly clean examples of the sounds to be learned (Hoff, 2009).

The Role of Infant-Directed Speech

•In addition to regulating attention and arousal, infant-directed speech may also support the language acquisition process.

•Laboratory tests conducted by Liu, Kuhl, &Tsao in 2003.

•On one study, Hirsh-Pasek and associates (1987) presented 7-10-month-old infants with tape-recorded samples of child-directed speech into which pauses had been inserted. In some of the samples, the pauses had been inserted at clause boundaries; for other samples, the pauses had been inserted within clause.

•Subsequent study by Kemler-Nelson, Hirsh-Pasek, Jusczyk, and Cassidy (1989) using the same procedure

• Please see page 8.

Prosody

•According to Hoff (2009), prosody is the intonation contour of speech.

• Please see page 5 (2).

Prosodic Bootstrapping HypothesisThe proposal that infants find important clues to language

structure in the prosodic characteristics of the speech signal is known Prosodic bootstrapping hypothesis.(Morgan & Demuth, 1996).

Prosodic features of speech, which tend to be exaggerated in speech to children may provide cues to syntactic structure (Hoff, 2009).

Examples: Pauses and changes in the intonation tend to occur at phrase boundaries (“Little Red Riding Hood pause lived with her mother pause at the edge of the woods”). On pages 9-10

Phonological Bootstrapping Hypothesis

•A more encompassing proposal, that properties of the sound signal other than prosody contribute to language learning, is known as Phonological Bootstrapping Hypothesis (Hoff, 2009).

•Children use phonological cues to break into grammatical structure

• On page 10

Cultural differences in the speech addressed to children

•Although it is often claimed that the special features of infant-directed speech are universal, there are dissenting voices (Ingram, 1995; Ratner &Pye, 1984).

•The fact that language acquisition is universal whereas infant-directed speech may not be raises the question of how important the properties of infant-directed speech can be in explaining language acquisition (Hoff, 2009).

B. Phonological Development During the Early Language Acquisition

•The appearance of a child’s first word is not a major landmark in phonological development.

•Phonological development proceeds relatively seamlessly through the transition from the pre-linguistic to the linguistic period.

•During the first year of life, infants produce a variety of vocalizations, beginning with simple cries at birth and progressing through ordered sequence of stages to complex babbling with identifiable syllables and adult-like intonation patterns.

Two General Pre-Linguistic Categories•Stages of Prespeech Vocal Development•1. Reflexive Crying and Vegetative Soundssounds that accompany the biological functions of breathing, sucking, and so on.

2. Cooing and laughter At around 6 to 8 weeks of age, infants start cooing. Babies produce their first laughter around the age of 16 weeks.

•3. Vocal Play the period between 16 weeks and 30 weeks has been called the period of vocal play (Stark, 1986), or the expansion stage (Oller, 1980). In this stage, the variety of different consonant-like and vowel-like sounds that infants produce increases.

-growing repertoire and the combination of different sounds

-squeals, growls, and a variety of “friction noises”

•2-3 months•-velars such as [g] and [k]•6-9 months of age•-articulated in front of the mouth•- [m], [n], [p], [b] and [d]

•Reduplicated Babbling

•4. Reduplicated Babbling (sometime around 6 to 9 months of age)

•-the quality of infant’s vocalization changes, and the infants start to babble.

• -Also known as canonical or reduplicated babbling

•-presence of true syllables, and these syllables produced in reduplicated series of the same consonant and vowel combination such as [dada] or [nanana].

•The appearance of canonical babbling is a major landmark in the infant’s prespeech development (Hoff, 2009).

•Canonical babbling is the first development that distinguishes the vocal development of hearing children from that of deaf children (Hoff, 2009).

•Nonreduplicated Babbling (variegated babbling)

•The range of consonants and vowels infants produce expands further.

• Infants combine different consonant + vowel and consonant + vowel + consonant syllables into series, unlike the repetitive series that characterized the first canonical babbling.

Models of Phonological Development•1. Behaviorist model•Reseracher attempted to account for

children's phonological development using the behaviorist mechanisms of imitation and reinforcement (Skinner, 1957; 1960).

•According to this model,babies produce sounds they do because they imitate the sounds they hear and because they receive positive reinforcement for doing so.

•Overtime, the sounds babies produce come to match the sounds of the target language because these are the sounds that babies have imitated and that have been reinforced.

•according to this proposal, a responsive environment does seem to support vocal development and also language development.

2. Biologically Based Theories•Some researchers argue persuasively that the

biological factors underlying the human motor capacity to produce speech shape both the course of phonological development and its ultimate result--namely the phonological properties of the world's languages.

•According to J.L. Locke (J.L. Locke, 1983; J.L. Locke & Pearson, 1992), infants' first sounds are the sounds the human vocal apparatus is most inclined to produce, given its anatomical and physiological characteristics. sound production is shaped by the development of motor capacity.

3. Cognitive Problem-Solving Approach•A long-standing view of phonological development is that children figure out the phonology of their language as a solution to the problem of how to sound like adults and to distinguish among the words they know when others talk to them (Ferguson & Farwell, 1975; Macken & Ferguson, 1983).

•This model of phonological development is associated with the view that, initially, children's word representations are whole-word representations and only later, when a child's capacity for mental representation is sufficient, are words analyzed into their segmental components, with contrasting features.

•Roman Jacobson in 1941 holds that children represent the underlying structure of the sounds of words from the very beginning of language.

4. The Connectionist Approach

•According to this model, children make appropriations in learning sounds through mapping rules orphonological processes.

•A central tenet of connectionism is a belief that rules are not necessary to describe the regularities of human behavior (Hoff, 2009).

Common Phonological Processes in Children's Speech•Whole-word processes

-weak syllable deletion: omission of an unstressed syllable in the target word

on words like banana, butterfly

Reduplication: production of two identical syllables based on one of the syllables in the target word

hello [jojo]bottle [baba] Consonant cluster reductioncracker

•According to this model, children err because their connections are not yet adult-like (Hoff, 2009).

Stages of Pre-Linguistic Development •Stage 1 (Reflexive vocalizations- birth to

two months) - This stage is characterized by a mojority

of reflexive vocalizations such as crying and fussing and vegetative sounds, like coughing, bruping and sneezing.

Stage 2 Cooing and Laughter

•During this stage, infants begin to make comfort-state vocalizations called cooing or going sounds.

•these vocalizations seem to be produced from the back of the mouth, with velar consonants and back vowels.

Stage 3 Vocal Play- four to six months•During this stage, the variety of different

consonant-like and vowel-like sounds that infants produce increases.

Stage 4 (Canonical Babbling- six months and older)•The prime feature of this period is the

appearance of sequences of consonant-vowel syllabus with adult-like timing.

•The quality of infant's vocalizations changes, and the infants start to babble.

Stage 5 (Jargon stage-10 months and older)

•the last stage of babbling overlaps with the early period of meaningful speech, and is characterized by stringsof sounds and syllables uttered with the rich variety of stress and intonational patterns. this kind of output is known by such names as conversational babble, modulated babble, or jargon.