title: Application of Linear Discriminant Analysis to the Long-term Averaged Spectra of Simulated Disorders of Oral-Nasal Balance.
abstract: Acoustic studies of oral-nasal balance disorders to date have focused on hypernasality. However, in patients with cleft palate, nasal obstruction may also be present, so that hypernasality and hyponasality co-occur. In this study, normal speakers simulated different disorders of oral-nasal balance. Linear discriminant analysis was used to create a tentative diagnostic formula based on the long-term averaged spectra (LTAS) of the speech stimuli.
  
  
  
  Eleven female participants were recorded while reading nonnasal and nasal speech stimuli. LTASs of the recordings were run for their normal oral-nasal balance and their simulations of hyponasal, hypernasal, and mixed oral-nasal balance. The amplitude values (in decibels) were extracted in 100-Hz intervals over a range of 4 kHz.
  
  
  
  A repeated-measures analysis of variance of the normalized amplitudes revealed a resonance condition-frequency band amplitude interaction effect (P < .001). A linear discriminant analysis of the participants' LTAS led to formulas correctly classifying 80.7% of the oral-nasal balance conditions.
  
  
  
  The simulations produced distinctive spectra enabling the creation of formulas that predicted the oral-nasal balance above chance level. Future research with speakers with oral-nasal balance disorders will be needed to investigate the potential of this approach for the clinical diagnosis of disorders of oral-nasal balance.
authors.forename: Gillian
authors.initials: G
authors.lastname: de Boer
authors.forename: Tim
authors.initials: T
authors.lastname: Bressmann
mesh_terms: D000328:Adult; D002972:Cleft Palate / Q000503:physiopathology; D016002:Discriminant Analysis; D005260:Female; D006801:Humans; D009666:Nose; D013068:Speech Production Measurement; D014833:Voice Quality; D055815:Young Adult
keywords: acoustics; hypernasality; hyponasality; mixed nasality; spectrography