title: Vocal interaction between children with Down syndrome and their parents.
abstract: OBJECTIVE
  The purpose of this study was to describe differences in parent input and child vocal behaviors of children with Down syndrome (DS) compared with typically developing (TD) children. The goals were to describe the language learning environments at distinctly different ages in early childhood.
  
  
  METHODS
  Nine children with DS and 9 age-matched TD children participated; 4 children in each group were ages 9-11 months, and 5 were between 25 and 54 months. Measures were derived from automated vocal analysis. A digital language processor measured the richness of the child's language environment, including number of adult words, conversational turns, and child vocalizations.
  
  
  RESULTS
  Analyses indicated no significant differences in words spoken by parents of younger versus older children with DS and significantly more words spoken by parents of TD children than parents of children with DS. Differences between the DS and TD groups were observed in rates of all vocal behaviors, with no differences noted between the younger versus older children with DS, and the younger TD children did not vocalize significantly more than the younger DS children.
  
  
  CONCLUSIONS
  Parents of children with DS continue to provide consistent levels of input across the early language learning years; however, child vocal behaviors remain low after the age of 24 months, suggesting the need for additional and alternative intervention approaches.
authors.forename: Kathy S
authors.initials: KS
authors.lastname: Thiemann-Bourque
authors.forename: Steven F
authors.initials: SF
authors.lastname: Warren
authors.forename: Nancy
authors.initials: N
authors.lastname: Brady
authors.forename: Jill
authors.initials: J
authors.lastname: Gilkerson
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Richards
mesh_terms: D000367:Age Factors; D002675:Child, Preschool; D003142:Communication; D004314:Down Syndrome / Q000175:diagnosis* / Q000628:therapy; D005260:Female; D006801:Humans; D007223:Infant; D007805:Language Development Disorders / Q000175:diagnosis / Q000628:therapy; D008297:Male; D010287:Parent-Child Relations; D010700:Phonetics; D012660:Semantics; D013068:Speech Production Measurement; D014705:Verbal Behavior; D014825:Vocabulary