Vocabulary development is a process by which people acquire words. Babbling shifts towards meaningful speech as infants grow and produce their first words around the age of one year. In early word learning, infants build their vocabulary slowly. By the age of 18 months, infants can typically produce about 50 words and begin to make word combinations. In order to build their vocabularies, infants must learn about the meanings that words carry. The mapping problem asks how infants correctly learn to attach words to referents. Constraints theories, domain-general views, social-pragmatic accounts, and an emergentist coalition model have been proposed to account for the mapping problem. From an early age, infants use language to communicate. Caregivers and other family members use language to teach children how to act in society. In their interactions with peers, children have the opportunity to learn about unique conversational roles. Through pragmatic directions, adults often offer children cues for understanding the meaning of words. Throughout their school years, children continue to build their vocabulary. In particular, children begin to learn abstract words. Beginning around age 3–5, word learning takes place both in conversation and through reading. Word learning often involves physical context, builds on prior knowledge, takes place in a social context, and includes semantic support. The phonological loop and serial order short-term memory may both play an important role in vocabulary development.
Early word learning Infants begin to understand words such as "Mommy", "Daddy", "hands" and "feet" when they are approximately 6 months old. Initially, these words refer to their own mother, or father, or hands, or feet. Infants typically produce their first words at around one year of age. Infants' first words are normally used in reference to things that are of importance to them, such as objects, body parts, people, and relevant actions. Also, the first words that infants produce are mostly single-syllabic or repeated single syllables, such as "no" and "dada". By 12 to 18 months of age, children's vocabularies often contain words such as "kitty", "bottle", "doll", "car" and "eye". Children's understanding of names for objects and people usually precedes their understanding of words that describe actions and relationships. "One" and "two" are the first number words that children learn between the ages of one and two. Infants must be able to hear and play with sounds in their environment, and to break up various phonetic units to discover words and their related meanings.
Development in oral languages
Studies related to vocabulary development show that children's language competence depends upon their ability to hear sounds during infancy. Infants' perception of speech is distinct. Between six and ten months of age, infants can discriminate sounds used in the languages of the world. By 10 to 12 months, infants can no longer discriminate between speech sounds that are not used in the language(s) to which they are exposed. Among six-month-old infants, seen articulations (i.e. the mouth movements they observe others make while talking) actually enhance their ability to discriminate sounds, and may also contribute to infants' ability to learn phonemic boundaries. Infants' phonological inventory is typically completed between the ages of 18 months and 7 years. Children's phonological development normally proceeds as follows: 6–8 weeks: Cooing appears 16 weeks: Laughter and vocal play appear 6–9 months: Reduplicated (canonical) babbling appears 12 months: First words use a limited sound repertoire 18 months: Phonological processes (deformations of target sounds) become systematic 18 months–7 years: Phonological inventory completion At each stage mentioned above, children play with sounds and learn methods to help them learn words. There is a relationship between children's prelinguistic phonetic skills and their lexical progress at age two: failure to develop the required phonetic skills in their prelinguistic period results in children's delay in producing words. Environmental influences may affect children's phonological development, such as hearing loss as a result of ear infections. Deaf infants and children with hearing problems due to infections are usually delayed in the beginning of vocal babbling.
Babbling
Babbling is an important aspect of vocabulary development in infants, since it appears to help practice producing speech sounds. Babbling begins between five and seven months of age. At this stage, babies start to play with sounds that are not used to express their emotional or physical states, such as sounds of consonants and vowels. Babies begin to babble in real syllables such as "ba-ba-ba, neh-neh-neh, and dee-dee-dee," between the ages of seven and eight months; this is known as canonical babbling. Jargon babbling includes strings of such sounds; this type of babbling uses intonation but doesn't convey meaning. The phonemes and syllabic patterns produced by infants begin to be distinctive to particular languages during this period (e.g., increased nasal stops in French and Japanese babies), though most of their sounds are similar. There is a shift from babbling to the use of words as the infant grows.
… excerpt ends here. Continue reading the full article.
