Children with Down syndrome (DS) commonly have special difficulty
acquiring grammar and expressive vocabulary, and studies have
articulated that at least from early school ages, their speech
production skills also are weaker than can be expected by their
intelligence scores. During the babbling stages, however, children with
DS have predominantly been found to produce canonical syllables nearly
within a timeframe prescribed. The purpose of this book is to define
whether early phonological development in children with DS can best be
characterized as delayed but predictable based on intellectual age, as
is the case for early comprehension of vocabulary and invalid syntax, or
whether, like vocabulary and grammatical production, speech production
is more severely impaired than could be predicted by the children's
cognitive capabilities alone. Also, explore the extent to which early
vocabulary delays are associated with deficits in speech sound
production.