title: The relationship between nasalance scores and nasality ratings obtained with equal appearing interval and direct magnitude estimation scaling methods.
abstract: OBJECTIVE
  To assess the nasalance/nasality relationship and Nasometer test sensitivity and specificity when nasality ratings are obtained with both equal appearing interval (EAI) and direct magnitude estimation (DME) scaling procedures. To test the linearity of the relationship between nasality ratings obtained from different perceptual scales. STIMULI: Audio recordings of the Turtle Passage.
  
  
  METHODS
  Participants' nasalance scores and audio recordings were obtained simultaneously. A single judge rated the samples for nasality using both EAI and DME scaling procedures.
  
  
  METHODS
  Thirty-nine participants 3 to 17 years of age. Across participants, resonance ranged from normal to severely hypernasal.
  
  
  METHODS
  Nasalance scores and two nasality ratings.
  
  
  RESULTS
  The magnitude of the correlation between nasalance scores and EAI ratings of nasality (r  =  .63) and between nasalance and DME ratings of nasality (r  =  .59) was not significantly different. Nasometer test sensitivity and specificity for EAI-rated nasality were .71 and .73, respectively. For DME-rated nasality, sensitivity and specificity were .62 and .70, respectively. Regression of EAI nasality ratings on DME nasality ratings did not depart significantly from linearity.
  
  
  CONCLUSIONS
  No difference was found in the relationship between nasalance and nasality when nasality was rated using EAI as opposed to DME procedures. Nasometer test sensitivity and specificity were similar for EAI- and DME-rated nasality. A linear model accounted for the greatest proportion of explained variance in EAI and DME ratings. Consequently, clinicians should be able to obtain valid and reliable estimates of nasality using EAI or DME.
authors.affiliation: University of Nevada, School of Medicine, Department of Speech Pathology and Audiology, Reno, Nevada 89557, USA. tbrancamp@medicine.nevada.edu
authors.forename: Tami U
authors.initials: TU
authors.lastname: Brancamp
authors.forename: Kerry E
authors.initials: KE
authors.lastname: Lewis
authors.forename: Thomas
authors.initials: T
authors.lastname: Watterson
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D006801:Humans; D016014:Linear Models; D009666:Nose; D015588:Observer Variation; D011601:Psychophysics; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D013068:Speech Production Measurement / Q000295:instrumentation / Q000379:methods*; D014832:Voice Disorders / Q000175:diagnosis*; D014833:Voice Quality