The Correlation Between Perceptual Ratings and Nasalance Scores in Resonance Disorders: A Systematic Review

Abstract

Introduction: Assessment of resonance characteristics is essential in research and clinical practice in individuals with velopharyngeal impairment. The purpose of this study was to systematically review correlations between auditory-perceptual ratings and nasalance scores obtained by a nasometer in individuals with resonance disorders and to identify factors that affected the correlations between these two measures. Method: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic search was conducted for studies reporting a correlation between nasality ratings and nasalance scores using six electronic databases based on predefined inclusion and exclusion criteria. Results: A total of 27 studies were included in this systematic review. Characteristics of study components including participants, types of assessment and stimuli, correlation coefficients, and reliability values of each study were identified, and a narrative synthesis was conducted. The methodological quality of each study was also appraised. The correlation level between nasalance values and nasality ratings varied from nonsignificant to strong (r =.92). The quality rating scores of the selected studies ranged from 44% to 94%, with an average score of 75%. Discussion: Factors that did or did not affect the varied correlation between nasality ratings and nasalance scores were discussed. Speech stimuli and the listeners’ background were associated with correlations between the two mea-sures. In addition, the sex of the speakers could be a factor affecting its correla-tion. However, the types of perceptual scales and listening conditions did not influence its correlations between the two measures.