title: Validity and repeatability of level-independent HL to SPL transforms.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the reliability and validity of the real ear to coupler difference (RECD) and the real ear to dial difference (REDD) in predicting real ear SPL (RESPL).
  
  
  METHODS
  The RESPL, RECD, and REDD were measured in the right ear of 24 normal-hearing subjects using probe microphone equipment and both insert and supra-aural earphones. The phones and probe tube were removed and replaced, and the RECD and REDD were remeasured.
  
  
  RESULTS
  RESPL was predicted using the RECD for insert earphone data and the REDD for supra-aural earphone data. Reliability estimates were calculated as the difference between test and retest values for the RECD and REDD. Validity estimates were calculated as the difference between measured and predicted RESPL. Results indicate that the RECD and REDD have equal and high reliability and validity in predicting RESPL.
  
  
  CONCLUSIONS
  It is concluded that the RECD and REDD may be used as level-independent HL to SPL transforms as a substitute for in situ audiometric procedures.
authors.affiliation: Hearing Health Care Research Unit, School of Communication Sciences and Disorders, University of Western Ontario, London, Canada.
authors.forename: S D
authors.initials: SD
authors.lastname: Scollie
authors.forename: R C
authors.initials: RC
authors.lastname: Seewald
authors.forename: L E
authors.initials: LE
authors.lastname: Cornelisse
authors.forename: L M
authors.initials: LM
authors.lastname: Jenstad
mesh_terms: D000328:Adult; D001301:Audiometry, Pure-Tone / Q000379:methods*; D005260:Female; D006309:Hearing / Q000502:physiology*; D006310:Hearing Aids; D006801:Humans; D008297:Male; D015203:Reproducibility of Results