title: Comparison of nasal acceleration and nasalance across vowels.
abstract: OBJECTIVE
  The purpose of this study was to determine the performance of normalized nasal acceleration (NNA) relative to nasalance as estimates of nasalized versus nonnasalized vowel and sentence productions.
  
  
  METHODS
  Participants were 18 healthy speakers of American English. NNA was measured using a custom sensor, and nasalance was measured using the KayPentax Nasometer II. Speech stimuli consisted of CVC syllables with the vowels (//, /æ/, /i/, /u/) and sentences loaded with high front, high back, low front, and low back vowels in both nasal and nonnasal contexts.
  
  
  RESULTS
  NNA showed a small but significant effect of the vowel produced during syllable stimuli but no significant effect of vowel loading during sentence stimuli. Nasalance was significantly affected by the vowel being produced during both syllables and sentences with large effect sizes. Both NNA and nasalance were highly sensitive and specific to nasalization.
  
  
  CONCLUSIONS
  NNA was less affected by vowel than nasalance. Discrimination of nasal versus nonnasal stimuli using NNA and nasalance was comparable, suggesting potential for use of NNA for biofeedback applications. Future work to improve calibration of NNA is needed to lower intersubject variability.
authors.affiliation: Correspondence to Cara E. Stepp: cstepp@bu.edu.
authors.forename: Elias B
authors.initials: EB
authors.lastname: Thorp
authors.forename: Boris T
authors.initials: BT
authors.lastname: Virnik
authors.forename: Cara E
authors.initials: CE
authors.lastname: Stepp
mesh_terms: D061725:Accelerometry / Q000295:instrumentation / Q000379:methods; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D009666:Nose / Q000502:physiology*; D010700:Phonetics; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013060:Speech / Q000502:physiology*; D013061:Speech Acoustics; D013067:Speech Perception; D013068:Speech Production Measurement / Q000295:instrumentation* / Q000379:methods; D014833:Voice Quality / Q000502:physiology*; D055815:Young Adult
keywords: acoustics; nasalance; nasalization; resonance disorders; velopharyngeal dysfunction