title: Alternative metrics for real-ear-to-coupler difference average values in children.
abstract: BACKGROUND
  Ideally, individual real-ear-to-coupler difference (RECD) measurements are obtained for pediatric hearing instrument-fitting purposes. When RECD measurements cannot be obtained, age-related average RECDs based on typically developing North American children are used. Evidence suggests that these values may not be appropriate for populations of children with retarded growth patterns.
  
  
  OBJECTIVE
  The purpose of this study was to determine if another metric, such as head circumference, height, or weight, can be used for prediction of RECDs in children.
  
  
  METHODS
  Design was a correlational study. For all participants, RECD values in both ears, head circumference, height, and weight were measured.
  
  
  METHODS
  The sample consisted of 68 North American children (ages 3-11 yr).
  
  
  METHODS
  Height, weight, head circumference, and RECDs were measured and were analyzed for both ears at 500, 750, 1000, 1500, 2000, 3000, 4000, and 6000 Hz. A backward elimination multiple-regression analysis was used to determine if age, height, weight, and/or head circumference are significant predictors of RECDs.
  
  
  RESULTS
  For the left ear, head circumference was retained as the only statistically significant variable in the final model. For the right ear, head circumference was retained as the only statistically significant independent variable at all frequencies except at 2000 and 4000 Hz. At these latter frequencies, weight was retained as the only statistically significant independent variable after all other variables were eliminated.
  
  
  CONCLUSIONS
  Head circumference can be considered as a metric for RECD prediction in children when individual measurements cannot be obtained. In developing countries where equipment is often unavailable and stunted growth can reduce the value of using age as a metric, head circumference can be considered as an alternative metric in the prediction of RECDs.
authors.affiliation: Department of Communication Disorders, Auburn University, Auburn; AL.
authors.forename: Judith T
authors.initials: JT
authors.lastname: Blumsack
authors.affiliation: Department of Communication Disorders, Auburn University, Auburn; AL.
authors.forename: Sandra
authors.initials: S
authors.lastname: Clark-Lewis
authors.affiliation: Department of Communication Disorders, Auburn University, Auburn; AL.
authors.forename: Kelli M
authors.initials: KM
authors.lastname: Watts
authors.affiliation: Department of Communication Disorders, Auburn University, Auburn; AL.
authors.forename: Martha W
authors.initials: MW
authors.lastname: Wilson
authors.affiliation: Department of Educational Leadership, Foundations, and Technology, Auburn University, Auburn, AL.
authors.forename: Margaret E
authors.initials: ME
authors.lastname: Ross
authors.affiliation: Department of Communication Disorders, Auburn University, Auburn; AL.
authors.forename: Lindsey
authors.initials: L
authors.lastname: Soles
authors.affiliation: Department of Communication Disorders, Auburn University, Auburn; AL.
authors.forename: Cydney
authors.initials: C
authors.lastname: Ennis
mesh_terms: D002508:Cephalometry; D002648:Child; D002675:Child, Preschool; D004423:Ear / Q000033:anatomy & histology; D004867:Equipment Design; D005260:Female; D006309:Hearing; D006310:Hearing Aids; D006320:Hearing Tests; D006801:Humans; D012886:Skull