Speech Development Flashcards
Pre-Language speech development
The lungs provide the energy source for most of the sounds of speech
Sounds are made when the flow of air is obstructed and r by the vocal folds or tongue or the lips
Range of infant vocalizations is limited due to:
Size and placement of tongue in relation to vocal cavity
As higher mammals to chimps and young children, we can cognitively not choke so therefore our vocal folds can be lower to produce more speech – Must be an adaptive advantage of speech to allow for the risk of chocking
Different psychologists describe slightly different stages in speech sound development (Oller, 1980; Stark, 1980), however the generally accepted phases are:
Crying is a fixed signal (They do not vary across individuals), communicates info about the child’s internal state (Hunger etc). unintentional
Vegetative sounds arise from swallowing and digestion – burping, coughing etc. unintentional.
Quasi-vowels are produced by releasing air with a relaxed vocal tract. Resemblance to the sounds of speech is coincidental, but they may be important in giving the infant experience of producing vowel-like sounds.
Cooing (from about 8 weeks) Children start moving their vocal tracts. Often associated with being content and so can be used as communication
Laughter occurs around 16 weeks – At first it is a reflex, later children come to laugh playfully and apparently communicatively.
Vocal play (from about 16 weeks) What Oller (2000) calls the “expansion stage” , Production of “full vowels” Infants toy with sounds produced with the vocal tract closed, such as the raspberry
Reduplicated (Canonical) babbling (from about 36 weeks) Produce adult-like syllables, but in repetitive sequences, such as dada, baba etc. Once programmed the sound thy can’t stop themselves and repeat the sound over and over
Nonreduplicated babbling (from about 48 weeks) Produce adult-like syllables in non-repetitive sequences that sounds very much like speech Prosody (rhythms of speech) becomes clearly apparent for the first time
What is the function of these early early stages of development?
The early passage of development seems to be very stable across children, but there is some variation
Leonard, Newhoff and Meselam (1980)
- the most common sounds used in babbling were also most common used in words
McGillion, 2016
- Age at which Canonical (reduplicated) Babbling predicted word onset alone, and both babbling and Age at which pointing (an important skill in early communication) predicted vocabulary at 18m
Oller and Eilers (1988) reported that deaf children do not produce canonical babbling in their first year (usually seen at about 10 months in hearing children) Shows that experience is involved in speech
Babbling is not shaped by experience
Locke (1983)
-found little variation between the repertoire of sounds produced in babbling over children acquiring each of 15 languages
Vihman 1992
-reports that /h/ is among the sounds most frequently produced by French children even though French contains no /h/ sounds
Social influences
Social interaction influence
Goldstein and Schwade (2008)
- Parents produced sounds to 9mths that were either Contingent on (immediately following) their children’s vocalisation, OR at set intervals that had nothing to do with children’s behaviour
-The quality of children’s productions was improved by contingent feedback in ways that depended on the nature of the feedback
Production of sound that are somewhat social is important in speech development
Bloom et al (1987)
- infants increase their vocalizations when there is an adult vocally responding
- infants’ vocalisations were more “speech-like” when the adults vocalisations were contingent on the infants vocalisations
Papoušek & Papoušek (1989) analyzed recordings of a number of natural mother infants interactions. The occurrence of vocal matching was analysed
- At 2 months of age 27% of infant vocalizations were produced as matches of maternal utterances
- At 5 months of age 43% of infant vocalizations were produced as matches
Early comprehension
Evidence for in utero speech discrimination
DeCasper and Fifer (1980)
-Day old Infants showed a preference for their mother’s voice
Kisilevsky et al (2003)
- Played 38 week old fetuses recordings of their mother’s and a stranger’s voice
- Their heart rates went up in response to their mother’s voice and down in response to the strangers
How does experience effect sound perception?
Mehler et al (1988)
-Newborns born to French-speaking mothers played recordings of French and of Russian
-They sucked more in response to French that to Russian
Werker and Tees (1984)
- Hindi and Inslekepmx (language of native Salish of British Columbia) both contain consonant contrasts that English does not
- Using head turn preference found that 6-8 month old English speaker could make distinction but 10-12 month olds couldn’t
- Hindi learning and Inslekepmx-learning 11-12 month olds were still able to make distinction
Pre word spurt vocab knowledge - Protowords
Adult speakers of English know at least 60,000 words, By age six the average child knows 14,000 words (Carey, 1978)
Children’s earliest word-like productions are not usually conventional words, but rather what have been called “protowords” These are sounds used consistently by children with consistent meanings but which bear no resemblance to conventional words
Path to protowords
- First be gesture (hands flung out to the sides, pals up) which is later replaced by bye and all gone at 1yr8 and 1yr9 (Vihman 1985)
- Can be gesture and sound combo (Babu + Clap = Bravo)
Words are typically used to refer to things (Tree Picture of a tree)
It is not clear that children’s early words meet this description
Pre word spurt vocab knowledge - Context specific
Words are typically used to refer to things (Tree Picture of a tree)
At 9 months Alison would say “car” when looking down on a car from the apartment window, but wouldn’t say it when close to car or looking at a picture of a car (L. Bloom 1973)
“duck” when hitting a toy duck off the edge of the bathtub. He never said “duck” while playing with ducks in other situations, or looking at real ducks (Barrett, 1986)
Use of a word in response to an object is not usually taken to be reference. Words must “stand for” their referents not simply “go with them”
Determining which of these a child’s word use is can be extremely difficult
Harris et al (1988) found that the four mothers did use the words in contexts other than that in which the child employed them
However, they also found that 18 out of the 22 context-bound words discovered were being used with the meaning with which the mothers most frequently used them
Overgeneralisation and Why a word spurt at 50 words
Early in development, children will often “overgeneralise” – using words to refer to a broader set of objects that is conventionally signified by that word
What are the boundaries of the word? – kids need to learn to generalize from a picture of the moon to other contexts – words are not context restricted but specific
Over generalizing that everything that s round is the moon
Composition of vocab at 50 words (Hamilton, Plunkett & Schafer, 2000) – word spurt (suddenly learning lots of nouns)
- Behrend (1990) argues that is the results of the onset/maturation of internal word-learning constraints
- -Genetic predisposition to mature around 18-24 month and so are able to learn words
- McShane (1980) - children have “naming insight” Sudden realization that words relate to things
