Chapter 46: Speech and Language Development

Speech and Language Development

Speech and language impairment affects a median of 5.95% of children. Particular factors are known to place children at greater risk of delay including low gestational age and birthweight. Although a proportion of neonates in these increased risk groups develop age-appropriate communication skills, others may demonstrate significant difficulties that have been shown to detrimentally impact on social and educational outcomes.

I. Patterns of development

1. Language

   1. Refers to the “complex and dynamic system of conventional symbols that is used in various modes for thought and communication.”

   2. It is a rule-based system that can be divided into five domains.

      • Phonology

      • Morphology

      • Syntax

      • Semantics

      • Pragmatics

2. Speech

   1. Defined as the articulation of speech sounds to convey language

   2. Achieved through the coordination of several systems

      • Respiratory

      • Phonatory

      • Laryngeal

      • Velopharyngeal

3. The development of speech and language is highly complex, but the majority of children attain these functions with relative ease. Table 46-1 summarizes normal speech and language development during childhood, although it is important to emphasize that variability exists in the timing of these milestones.

   1. Precursors of speech and language

      1. Develop in the first year of life.

      2. Up to 9 months of age, children are “preintentional communicators” whereby their actions are not produced with an intended purpose.

      3. Children's speech-motor control progresses from vowel-like sounds (with the articulators at rest) to the formation of well-formed and timed syllables.

      4. This form of babbling, known as canonical, precedes a child's first word, which typically occurs around 1 year of age.

   2. First words

      1. Typically consist of nouns, with verbs and adjectives appearing around 20 months.

      2. By 17 months of age, approximately 50% of children demonstrate a vocabulary of 50 words.

      3. Between 18 and 20 months, most children have experienced a rapid burst in vocabulary development and are beginning to produce two-word utterances.

      4. At 3 years of age, infants are able to form simple sentences consisting of three or more words that incorporate basic syntactic structures and grammatical markers.

      5. By age 5, children have acquired all the morphological markers of the English language, and are able to use a variety of simple and complex sentence types.

   3. Beginnings of speech development

      1. Children typically acquire sounds in an orderly sequence.

      2. There are a variety of speech classification systems proposed, with an enduring model being Shriberg's grouping of consonants according to their approximate order of acquisition (the “early-, middle-, and late-8”).

         • The “early-8” sounds consist of m, b, j (as in yes), n, w, d, p, h.

         • Followed by: t, ŋ (as in ring), k, g, f, v, ʧ (as in chair), ʤ (as in bridge) (the “middle-8”).

         • Followed by: ʃ (as in she), θ (as in thumb), s, z, ð (as in this), l, ɹ (as red), ʒ (as in measure) (the “late-8”).

      3. By 4 years of age, the majority of these sounds should be produced correctly and there is a ...