BABBLING AND EARLY WORDS

BABBLING AND EARLY WORDS
A child’s entrance into human society begins with the
onset of language development. Parents often ac-
knowledge this accomplishment upon hearing their
infant’s first words. Research on early language has
convinced scientists that the emergence of first words
is inseparable from important developmental mile-
stones that occur prior to the recording of these
words. Pre-speech vocalizations can be examined nar-
rowly within the verbal domain only, or can be ex-
plored in a wider scope as related to cognitive and
communicative developments that are established
during the first year of life. The study of pre-speech
vocalizations flourished during the last quarter of the
twentieth century. During the late 1970s and early
1980s, most efforts concentrated on describing the
sounds infants produce. In the 1990s, study of pre-
speech development expanded in several important
directions.
The Form of Infants’ Pre-Speech
Vocalizations
Pre-speech vocalizations are divided into reflex-
ive vocalizations (e.g., cries, coughs, hiccups), which
are related to the baby’s physical state, and nonreflex-
ive vocalizations (e.g., cooing, playful productions,
yelling), which contain phonetic and syllabic features
of speech. Both vowels and consonants appear in
nonreflexive vocalizations, and the most prevalent
syllable structure is a consonant followed by a vowel
(CV; e.g., \ba\, \du\, \ke\). The overall composition of
pre-speech vocalizations changes dramatically during
the first year of life. In the first six months, babies all
over the world sound alike. During this period, vowels
predominate and are supported by prolonged back
consonants (e.g., \k\, \g\). During the next six months,
the sound repertoire significantly expands, with a
marked shift toward more frontal consonants. John
Locke reported in 1993 that, by their first birthday,
American English-speaking infants produce stops
(\p\, \b\, \t\, \d\, \k\, \g\), nasals (\m\, \n\), and glides
(\w\, \j\).
Stages in the Development of Pre-Speech
Vocalizations
Developmental stages of pre-speech vocalizations
(e.g., as described by Carol Stoel-Gammon in 1998)
are not discrete, and vocalizations from previous
stages continue to be uttered subsequently. Novel
emergent behaviors define the beginning of a new
stage. Ages are assigned to each stage as estimates
only, because children differ greatly regarding the
timing for recording milestones of early language de-
velopment.
The first stage (from zero to two months), phona-
tion, is characterized mainly by fussing, crying, sneez-
ing, and burping, which bear little resemblance to
adult speech. The second stage (at two to three
months), cooing, begins when back vowels and nasals
appear together with velar consonants (e.g., \gu\,
\ku\). Cooing differs in its acoustic characteristics
from adult vocalizations and is recorded mainly
45during interactions with caregivers. In the third stage
(at four to six months), vocal play or expansion, sylla-
ble-like productions with long vowels appear.
Squeals, growls, yells, bilabial or labiodental trills,
and friction noises demonstrate infants’ playful ex-
ploration of their vocal tract capabilities during this
stage.
In the extremely important canonical babbling
stage (at seven to ten months), two types of produc-
tions emerge: reduplicated babbling—identical, re-
petitive sequences of CV syllables (e.g., \ma\ma\,
\da\da\); and variegated babbling—sequences of dif-
ferent consonants and vowels (e.g., CV, V, VC, VCV
= \ga\e\im\ada\). Such productions are not true
words, as they lack meaning. Canonical babbling is
syllabic, containing mainly frontal stops, nasals, and
glides coupled with lax vowels (e.g., \a\, \e\, \o\). The
emergence of canonical babbling is highly important,
holding predictive value for future linguistic develop-
ments. Oller and her colleagues in 1999 argued that
babies who do not produce canonical babbling on
time are at high risk for future speech and language
pathology, and should be carefully evaluated by a lan-
guage clinician.
In the fifth stage (at twelve to thirteen months),
jargon or intonated babble, infants produce long
strings of syllables having varied stress and intonation
patterns. Jargon sounds like whole sentences convey-
ing the contents of statements or questions, and often
co-occurs with real words. Yet, it lacks linguistic con-
tent or grammatical structure.
Pre-Speech Vocalizations in Different
Target Languages
The early interpretation of similarities in the
phonetic structure of babbling among infants who ac-
quire different languages (e.g., Japanese, Hebrew)
was that pre-speech vocalizations are universal. This
observation was explained by the strong constraints
of the mouth’s anatomical characteristics and by phys-
iological mechanisms controlling movements of the
tongue and palate. Cross-linguistic research in the
1990s revealed, however, that clear influences of seg-
mental and suprasegmental patterns (i.e., intonation
and stress) of the input are recognizable in pre-
speech vocalizations. This is particularly true during
the second half of the first year of life. In a longitudi-
nal comparative study by Bénédicte de Boysson-
Baradis (1999) of ten-month-old Spanish, English,
Japanese, and Swedish infants, the relative distribu-
tion of consonants in their canonical babbling resem-
bled the distribution of these segments in their
language. As babies grow, the segmental similarity be-
tween their babbling and early words increases. Sever-
al studies by Peter Jusezyk and colleagues on speech
perception indicate that infants’ sensitivity to the
acoustics and phonetics of languages increases with
age, influencing their ability to discriminate the se-
quences of sounds and syllable structures typical to
their own language. Indirect evidence for the role of
audition in the development of pre-speech vocaliza-
tions derives from studies on deaf children, who show
significant delays in the emergence of canonical bab-
bling and also a decreased variety of consonants ut-
tered from age eight months onward.
Mutual Imitation within Mother-Child
Interaction
In 1989 Metchthild and Hanus Papouˇ sek were
among the first researchers to point out that more
than 50 percent of two- to five-month-olds’ noncrying
vocalizations are either infant imitations of mothers’
previous vocalizations or mothers’ imitations of in-
fants’ previous vocalizations. They suggested that this
mutual vocal matching mechanism relates to the
emotional regulation of communication in the begin-
ning of life. Joanna Blake and Bénédicte de Boysson-
Bardies found in 1992 that infants tend to vocalize
more while manipulating small objects and especially
when adults are present. Edy Veneziano in 1988 ana-
lyzed vocal turn taking in pairs of nine- to seventeen-
month-old babies and their mothers. She reported
that, as children advance toward conventional lan-
guage, mothers’ imitations of what babies say be-
comes selective. Mothers imitate only those infant
vocalizations resembling conventional words, thus
signaling to the child what constitutes a linguistic
symbol with meaning.
Pre-Symbolic Productions in Hearing and
in Deaf Infants
Cumulative research on pre-speech vocalizations
clearly indicates that babbling is in fact structurally
and functionally related to early speech. Locke ar-
gued in 1996 that when variegated babbling emerges,
a consistent relation is identified between vocaliza-
tions and specific communicative functions (i.e., pro-
test, question, and statement). At around age
eighteen months, the child’s phonological system is
clearly shaped by the target language’s phonetic char-
acteristics, and at that time conventional words
emerge.
Indirect evidence for the developmental signifi-
cance of babbling was published in a revolutionary
1991 paper by Laura Petitto and Paula Marentette on
hand babbling in two deaf infants of signing mothers.
The argument was that these two infants (who were
recorded at ages ten, twelve, and fourteen months)
46 BABBLING AND EARLY WORDSproduced far more manual babbling than three
matched hearing infants at similar ages. The deaf in-
fants’ hand babbling also revealed phonetic features
of American Sign Language, suggesting that babbling
reflects infants’ innate ability to analyze phonetic and
syllabic components of linguistic input.
Pre-Speech Productions and First Words
or Signs
Early words are produced by the child in expect-
ed contexts, and hence are recognized by familiar lis-
teners as linguistic units conveying meanings. In 1999
Esther Dromi distinguished between comprehensible
and meaningful words. Comprehensible words are
phonetically consistent forms resembling adult words
that caregivers understand, but that do not yet convey
referential meanings. Meaningful words are symbol-
ic, arbitrary, and agreed-upon terms of reference.
Considerable variation exists in both the age of
speech onset and the rate of early lexical develop-
ment. Large-scale questionnaire data reported in
1994 by Fenson and his colleagues for English-
speaking typically developing children, cited the
range of vocabulary size for twelve- to thirteen-
month-olds at 0 to 67 different words, and for eigh-
teen- to nineteen-month-olds at 13 to 471 different
words. In 2000 Maital and her colleagues reported
very similar figures for Hebrew.
Early words are constructed from a limited set of
consonants, mainly stops, nasals, and glides. Syllable
structures in these words are usually CV, CVC, or
CVCV. Several researchers found that during the first
few months of lexical learning, many new words are
composed from segments that the child is already
using in babbling. A number of researchers have pro-
posed that patterns of lexical selection and avoidance
reflect the child’s production capabilities. When pro-
ductive vocabularies contain more than a hundred
different words, the influences of phonology on the
lexicon decline. Nevertheless, children who have rela-
tively larger lexicons of single words also show larger
inventories of sounds and syllable structures than
children with smaller productive lexicons. Precocious
word learners have much larger phonetic inventories
than typically developing children at age eighteen
months. The major semantic achievement in the first
few months of vocabulary learning is the ability to use
words referentially. Martyn Barrett and Esther
Dromi, who independently carried out detailed longi-
tudinal analyses of repeated uses of the same words
over time, have argued that some early words show
referential use from their outset, while other words
are initially produced only in very specific contexts.
Throughout the one-word stage, the phonology of
words improves, and meanings become symbolic and
arbitrary. A word initially produced in just one situa-
tion is now uttered in a much wider range of contexts,
until it becomes completely context free and referen-
tial. As words become conventional tools for express-
ing meanings, the amount of pre-speech vocalizations
declines and gradually disappears.
See also: INFANCY; LANGUAGE DEVELOPMENT
Bibliography
Barrett, Martyn. ‘‘Early Semantic Representations and Early Word
Usage.’’ In Stan Kuczay and Martyn Barrett eds., The Develop-
ment of Word Meaning. New York: Springer, 1986.
Blake, Joanna, and Bénédicte de Boysson-Bardies. ‘‘Patterns in
Babbling: A Cross-Linguistic Study.’’ Journal of Child Language
19 (1992):51–74.
de Boysson-Bardies, Bénédicte. How Language Comes to Children:
From Birth to Two Years. Cambridge, MA: MIT Press, 1999.
Dromi, Esther. Early Lexical Development. Cambridge, Eng.: Cam-
bridge University Press, 1987.
Dromi, Esther. ‘‘Early Lexical Development.’’ In Martyn Barrett
ed., The Development of Language. London: UCL Press, 1999.
Fenson, Larry, Philip S. Dale, Steven J. Reznick, Elizabeth Bates,
Donna Thal, and S. J. Pethick. Variability in Early Communica-
tion Development. Malden, MA: Blackwell, 1994.
Jusczyk, Peter W.  The Discovery of Spoken Language. Cambridge,
MA: MIT Press, 1997.
Locke, John L. The Child’s Path to Spoken Language. Cambridge,
MA: Harvard University Press, 1993.
Locke, John L. ‘‘Why Do Infants Begin to Talk? Language as an
Unintended Consequence.’’  Journal of Child Language 23
(1996):251–268.
Maital, Sharone L., Esther Dromi, Avi Sagi, and Marc H. Boren-
stein. ‘‘The Hebrew Communicative Development Inventory:
Language Specific Properties and Cross-Linguistic General-
izations.’’ Journal of Child Language 27 (2000):43–67.
Oller, Kimberly D., and Rebecca E. Eilers. ‘‘The Role of Audition
in Infant Babbling.’’ Journal of Child Language 59 (1988):441–
449.
Papouˇ sek, Metchthild, and Hanus Papouˇ sek. ‘‘Form and Function
of Vocal Matching in Interactions between Mothers and Their
Precanonical Infants.’’ First Language 9 (1989):137–158.
Petitto, Laura A., and Paula F. Marentette. ‘‘Babbling in the Manu-
al Mode: Evidence for the Ontogeny of Language.’’ Science
251 (1991):1493–1496.
Stoel-Gammon, Carol. ‘‘Role of Babbling and Phonology in Early
Linguistic Development.’’ In Amy M. Wetherby, Steven F.
Warren, and J. Reichle eds., Transitions in Prelinguistic Commu-
nication. Baltimore: Paul Brookes, 1997.
Veneziano, Edy. ‘‘Vocal-Verbal Interaction and the Construction of
Early Lexical Knowledge.’’ In M. D. Smith and John L. Locke
eds., The Emergent Lexicon: The Child’s Development of a Linguis-
tic Vocabulary. New York: Academic Press, 1988.
Vihman, Marilyn M. Phonological Development: The Origins of Lan-
guage in the Child. Cambridge, MA: Blackwell, 1996.
Esther Dromi