title: Audible television and decreased adult words, infant vocalizations, and conversational turns: a population-based study.
abstract: OBJECTIVE
  To test the hypothesis that audible television is associated with decreased parent and child interactions.
  
  
  METHODS
  Prospective, population-based observational study.
  
  
  METHODS
  Community.
  
  
  METHODS
  Three hundred twenty-nine 2- to 48-month-old children.
  
  
  METHODS
  Audible television. Children wore a digital recorder on random days for up to 24 months. A software program incorporating automatic speech-identification technology processed the recorded file to analyze the sounds the children were exposed to and the sounds they made. Conditional linear regression was used to determine the association between audible television and the outcomes of interest.
  
  
  METHODS
  Adult word counts, child vocalizations, and child conversational turns.
  
  
  RESULTS
  Each hour of audible television was associated with significant reductions in age-adjusted z scores for child vocalizations (linear regression coefficient, -0.26; 95% confidence interval [CI], -0.29 to -0.22), vocalization duration (linear regression coefficient, -0.24; 95% CI, -0.27 to -0.20), and conversational turns (linear regression coefficient, -0.22; 95% CI, -0.25 to -0.19). There were also significant reductions in adult female (linear regression coefficient, -636; 95% CI, -812 to -460) and adult male (linear regression coefficient, -134; 95% CI, -263 to -5) word count.
  
  
  CONCLUSIONS
  Audible television is associated with decreased exposure to discernible human adult speech and decreased child vocalizations. These results may explain the association between infant television exposure and delayed language development.
authors.affiliation: Center for Child Health, Behavior and Development, 1100 Olive Way, Ste 500, Seattle, WA 98101, USA. dachris@u.washington.edu
authors.forename: Dimitri A
authors.initials: DA
authors.lastname: Christakis
authors.forename: Jill
authors.initials: J
authors.lastname: Gilkerson
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Richards
authors.forename: Frederick J
authors.initials: FJ
authors.lastname: Zimmerman
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Garrison
authors.forename: Dongxin
authors.initials: D
authors.lastname: Xu
authors.forename: Sharmistha
authors.initials: S
authors.lastname: Gray
authors.forename: Umit
authors.initials: U
authors.lastname: Yapanel
mesh_terms: D000328:Adult; D001288:Attention; D002675:Child, Preschool; D003142:Communication; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007804:Language Development; D016014:Linear Models; D008144:Loudness Perception; D008297:Male; D009323:Natural Language Processing; D010287:Parent-Child Relations; D011446:Prospective Studies; D012984:Software; D013067:Speech Perception; D013690:Television; D014705:Verbal Behavior; D014861:Washington