title: Characteristics of nasal resonance and perceptual rating in prelingual hearing impaired adults.
abstract: OBJECTIVE
  Resonance problems in hearing impaired (HI) individuals have been described as aspects of nasality. However, there are limitations in being able to explain the range of resonance problems. Therefore, this study suggests a perceptual rating that will effectively explain the characteristics of resonance problems in HI individuals.
  
  
  METHODS
  Nasalance scores were obtained from 32 subjects in each of HI and normal hearing (NH) groups using a nasometer. The subjects were categorized into groups based on normal and abnormal nasalance ranges. The abnormal nasalance range group was further divided into hyper-, hypo-, and mixed-nasal groups. Nasalance scores were based the individuals performance in a series of passage and syllable tasks. The perceptual rating was evaluated using a newly introduced tool, 'vertical focus of resonance' (VFR), which focuses on the resonance energy in the frontal, throat, pharyngeal and nasal locations.
  
  
  RESULTS
  The NH group demonstrated a significantly lower nasalance score in the oral coupling and passage tasks than the HI group. Based on the results of nasalance correlation analysis, the HI group showed highly significant correlations between syllable and passage tasks, as contrasted with the NH group. There were significant differences in VFR between the nasalance types in both the NH and the HI groups.
  
  
  CONCLUSIONS
  The HI hyper-nasal group showed tendencies of velopharyngeal opening, as opposed to the HI hypo-nasal group which showed tendencies of velopharyngeal closure. The HI mixed-nasal group showed inappropriate coordination of velopharyngeal function. In the HI group, the results of VFR showed that the air flow and the resonance energy were not released from the cavity of resonance. The suggested VFR tool explains the focusing characteristics of resonance energy within a continuation of speech sound regardless of the phonetic environment. Therefore, VFR may be a useful tool in explaining the deviant resonance patterns of HI individuals.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Eun Yeon
authors.initials: EY
authors.lastname: Kim
authors.forename: Mi Sun
authors.initials: MS
authors.lastname: Yoon
authors.forename: Hyang Hee
authors.initials: HH
authors.lastname: Kim
authors.forename: Chung Mo
authors.initials: CM
authors.lastname: Nam
authors.forename: Eun Sook
authors.initials: ES
authors.lastname: Park
authors.forename: Sung Hwa
authors.initials: SH
authors.lastname: Hong