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Before you were able to add 2 + 2, you were creating your own original and
grammatically appropriate sentences. Most of us would have trouble stating our
language's rules for ordering words to form sentences.
Yet as preschoolers, you
comprehended and spoke with a facility that puts to shame your fellow college
students now struggling to learn a foreign language.
Receptive Language Children's language development moves from simplicity to
complexity. Infants start without language
(in fantis
means "not speaking"). Yet by
4 months of age, babies can discriminate speech sounds (Stager & Werker, 1997).
They can also read lips: They prefer to look at a face that matches a sound, so we
know they can recognize that
ah
comes from wide open lips and
ee
from a mouth
with corners pulled back (Kuhl & Meltzoff, 1982).
This period marks the
beginning of the development of babies'
receptive language,
their ability to
comprehend speech. At seven months and beyond, babies grow in their power to
do what you and and I find difficult when listening to an unfamiliar language:
segmenting spoken sounds into individual words. Moreover, their adeptness at this
task, as judged by their listening patterns, predicts their language abilities at ages 2
and 5 (Newman et al., 2006).
Productive Language Babies'
productive language,
their ability to produce words,
matures after their receptive language. Around 4
months of age, babies enter the
babbling stage, in which they spontaneously utter a variety of sounds, such as
ah-
goo.
Babbling is not an imitation of adult speech,
for it includes sounds from
various languages, even those not spoken in the household. From this early
babbling, a listener could not identify an infant as being, say, French, Korean, or
Ethiopian. Deaf infants who observe their Deaf parents
signing begin to babble
more with their hands (Petitto & Marentette, 1991). Before nurture molds our
speech, nature enables a wide range of possible sounds.
Many of these natural
babbling sounds are consonant-vowel pairs formed by simply bunching the tongue
in the front of the mouth
(da-da, na-na, ta-ta)
or by opening and closing the lips
(ma-ma),
both of which babies do naturally for feeding (MacNeilage & Davis,
2000).
By the time infants are about 10 months old, their babbling has changed so that a
trained ear can identify the language of the household (de Boysson-Bardies et al.,
1989). Sounds and intonations outside that language begin to disappear. Without
exposure to other languages, babies become functionally
deaf to speech sounds
outside their native language (Pallier et al., 2001). This explains why adults who
speak only English cannot discriminate certain Japanese sounds within speech, and
why Japanese adults with no training in English cannot
distinguish between the
English
r
and
l.
Thus,
la-la-ra-ra
may, to a Japanese-speaking adult, sound like the
same syllable repeated. A Japanese-speaking person told that the train station is