The relationship between the Nasality Severity Index 2.0 and perceptual judgments of hypernasality.
The Nasality Severity Index 2.0 (NSI 2.0) forms a new, multiparametric approach in the identification of hypernasality. The present study aimed to investigate the correlation between the NSI 2.0 scores and the perceptual assessment of hypernasality.



Speech samples of 35 patients, representing a range of nasality from normal to severely hypernasal, were rated by four expert speech-language pathologists using visual analogue scaling (VAS) judging the degree of hypernasality, audible nasal airflow (ANA) and speech intelligibility. Inter- and intra-listener reliability was verified using intraclass correlation coefficients. Correlations between NSI 2.0 scores and its parameters (i.e. nasalance score of an oral text and vowel /u/, voice low tone to high tone ratio of the vowel /i/) and the degree of hypernasality were determined using Pearson correlation coefficients. Multiple linear regression analysis was used to investigate the possible influence of ANA and speech intelligibility on the NSI 2.0 scores.



Overall good to excellent inter- and intra-listener reliability was found for the perceptual ratings. A moderate, but significant negative correlation between NSI 2.0 scores and perceived hypernasality (r=-0.64) was found, in which a more negative NSI 2.0 score indicates the presence of more severe hypernasality. No significant influence of ANA or intelligibility on the NSI 2.0 was observed based on the regression analysis.



Because the NSI 2.0 correlates significantly with perceived hypernasality, it provides an easy-to-interpret severity score of hypernasality which will facilitate the evaluation of therapy outcomes, communication to the patient and other clinicians, and decisions for treatment planning, based on a multiparametric approach. However, research is still necessary to further explore the instrumental correlates of perceived hypernasality.



The reader will be able to (1) describe and discuss current issues and influencing variables regarding perceptual ratings of hypernasality; (2) describe and discuss the relationship between the Nasality Severity Index 2.0, a new multiparametric approach to hypernasality, and perceptual judgments of hypernasality based on visual analogue scale ratings; (3) compare these results with the correlations based on a single parameter approach and (4) describe and discuss the possible influence of audible nasal airflow and speech intelligibility on the NSI 2.0 scores.
Department of Speech, Language and Hearing Sciences, Ghent University, Ghent, Belgium. Electronic address: Kim.Bettens@Ugent.be.
Kim
K
Bettens
Department of Speech, Language and Hearing Sciences, Ghent University, Ghent, Belgium; Rehabilitation Centre for Communication Disorders, Antwerp University Hospital, Wilrijk, Belgium.
Marc
M
De Bodt
Department of Otorhinolaryngology, Speech-Language Pathology, Sint-Augustinus General Hospital, Wilrijk, Antwerp, Belgium; Department of Speech-Language Therapy and Audiology, Faculty of Education, Health and Social Work, University College Ghent, Ghent, Belgium; Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.
Youri
Y
Maryn
Department of Speech, Language and Hearing Sciences, Ghent University, Ghent, Belgium.
Anke
A
Luyten
Department of Speech, Language and Hearing Sciences, Ghent University, Ghent, Belgium; Biomedical Physics, University of Antwerp, Antwerp, Belgium.
Floris L
FL
Wuyts
Department of Speech, Language and Hearing Sciences, Ghent University, Ghent, Belgium.
Kristiane M
KM
Van Lierde
D002648:Child; D006801:Humans; D009296:Nasal Cavity; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013065:Speech Intelligibility; D013068:Speech Production Measurement; D014681:Velopharyngeal Insufficiency / Q000175:diagnosis*; D014832:Voice Disorders / Q000175:diagnosis*; D014833:Voice Quality
Hypernasality; Nasality Severity Index 2.0; Perceptual judgment; Visual analogue scale