Babbling is the stage of language development during which children produce speech sounds arranged in nonsensical combinations, such as “bababa,” “deedeedee,” or “badegubu.” All normally developing children babble. Parents and family members may view babbling as an endearing but trivial behavior produced by infants; however, babbling represents a stage of language development during which the child is laying the foundation for future adult-like language production.
The Sounds Of Babbling
The first vocalizations produced by infants include crying, laughing, and cooing. When infants are between 2 and 3 months old, they begin to coo. Cooing infants produce sounds that most closely resemble the vowels a, e, and o. Cooing may be an extended single vowel as in “oooo” or “aaaa” or a complex series of vowels, “aaaeeeooo.” Babbling typically begins by the 6th month. Table 1 provides a summary of the types of utterances produced by the child in the first year.
Between the 6th and 7th months, infants gain greater control of jaw movements, enabling them to produce the vowels i and u and the consonants g and k.
Over time, infants begin producing the consonants m, n, p, b, and d. During this time, infants engage in vocal play. They may produce nonspeech sounds such as squealing, yelling, and growling. They may also produce raspberries, which are created when the tongue is extended through rounded lips and air is forced through the mouth.
Between 6 and 9 months, infants begin to combine a single consonant and vowel together in a long repetitive sequence, such as “bababababa” or “deedeedeedee.” Such sequences are characteristic of canonical babbling. Over time, infants’ babbling becomes more complex. Productions typically involve different syllables produced in the same utterance, as in “badegubu” or “deekidobu.” Such sequences are characteristic of variegated babbling. Between the ages of 12 and 14 months, infants’ babbling is likely to contain intonational contours or prosody. Infants may produce streams of speech sounds that have the melody of adult speech. It may sound as though the infant is making a statement or asking a question, even though they are not saying anything meaningful.
Development Of Babbling
Table 1 Types of Utterances Produced by a Child in the First Year
There are physical changes that occur in the young infant that make babbling possible. At birth, infants’ vocal structure closely resembles that of nonhuman primates, with a shorter vocal tract and a much higher larynx than adults. Before babbling can occur, the vocal tract must mature, and the infant’s larynx must descend from high in the nasal passage to a lower position in the throat. During the 3 months of life before the larynx descends, infants can eat and breathe simultaneously. Before the larynx descends, infants are incapable of producing complex speech sounds, such as syllables composed of consonant-vowel combinations. Infants are capable of producing cries, clicks, groans, and sighs. After the larynx descends, infants can produce cooing sounds, such as “ooo” and “aaa.” By the age of 4 months, the vocal tract more closely resembles that of adults, and babbling generally emerges. In the months following the descent of the larynx, infants’ vocalizations become more and more complex.
Research has shown that 95% of infants’ babbled vocalizations involve the 12 speech sounds that are most common across the world’s languages: m, d, j, p, h, b, w, t, n, k, g, and y. The vocalizations babbled by all infants are strikingly similar across the world, regardless of the infants’ native language. It is common for infants to produce speech sounds that are not among the speech sounds of their native language. For example, infants reared in English-speaking environments may produce
non-English speech sounds, such as the click sounds that occur in certain African languages. Likewise, infants reared in Japanese-speaking environments may produce speech sounds not occurring in Japanese, such as [r]. As infants mature, more of the speech sounds produced are those speech sounds heard in the environment in the language or languages of the home, and fewer of them are speech sounds from other languages. This phenomenon has been referred to as babbling drift.
When Babbling Is Delayed Or Does Not Occur
An absence or substantial delay of babbling may occur in infants born with certain medical conditions or infants with developmental disorders. For example, infants who have had a tracheotomy typically do not babble and show persistent abnormalities in their vocal patterns if their normal breathing is not restored by the second year of life.
Some infants may be unable to produce speech due to a disorder affecting the motor control system. This disorder is called apraxia. Infants with severe apraxia may not coo or babble and may fail to produce a first word. They may attempt to communicate by pointing and grunting. Less severe forms of apraxia may be characterized by a delay in the production of the first word. When words are produced, speech sounds that are difficult to articulate may be consistently replaced with speech sounds that are easier to articulate.
Babbling may also be delayed or completely absent in infants affected by autism. Autism is a disorder characterized by abnormal social development. Autism is typically accompanied by delays in language development and may be accompanied by mental retardation. Those with the severest forms of autism may not speak at all. Those with mild forms of autism may produce some speech, but the amount of speech that is produced is far less than that of the typical infant.
Babbling may be delayed in infants born with Down syndrome, a chromosomal abnormality that causes mental retardation. Approximately 1 in 800 infants is born with Down syndrome each year. Down syndrome children typically experience delays in language development. Down syndrome infants start the canonical babbling stage 2 months later than other infants do. However, when babbling does occur, it is similar to the babbling produced by normally developing infants. Due to abnormalities in the development of the vocal tracts, palates, and tongues of Down syndrome children, speech production is likely to be challenging for the Down syndrome child.
Babbling occurs without a delay in infants born with hearing impairments. Each year, approximately 1 in 1,000 children is born with a severe hearing loss. The early vocalizations made by profoundly deaf infants cannot be easily distinguished from those made by hearing infants. Deaf infants will cry, coo, and begin to babble. However, deaf infants are unlikely to produce repeated consonant–vowel syllables characteristic of the canonical babbling stage. The amount of babbling and the quality of the babbling produced by deaf infants may be less than that produced by hearing infants. Deaf infants who are exposed to sign language from birth develop sign language skills in the same stages as hearing infants develop speech and listening skills. Signed languages such as American Sign Language (ASL) are unique languages, each having its own rules of grammatical structure. Deaf infants who are exposed to a signed language will produce manual babbling—sequences of gestures that can be viewed as language practice. Manual babbling typically emerges around 10 months. In contrast, hearing infants who are exposed to a signed language during the first year of life produce very little manual babbling.
Summary
Babbling is a routine stage of language development, observed in all normally developing infants. Starting at the 6th month, infants practice the speech sounds that will later be used to form syllables, words, and sentences. Over time, the sequences that are babbled become more complex. By the end of the first year, infants have produced their first words. For infants with certain developmental disorders, babbling may be delayed or absent.
References:
- Hoff, E. (2001). Language development. Belmont, CA: Wadsworth/Thomson
- Ritchie, W. , & Bhatia, T. K. (1999). Handbook of child language acquisition. San Diego, CA: Academic Press.