Analysis of Nasalance according to Pattern of Phonation

Ahn, Cheol Min; Woo, Won Keun; Kim, Ki Hyung; Seo, Moon Sun; Seo, Beom Suk

Abstract

BACKGROUND AND OBJECTIVES
Various phonation patterns yield various voice characteristics. Voice therapy using nasal stimulatory sounds seems to facilitate phonation in voice disodered patients. Under the hypothesis that nasalance may be influenced by the pattern of phonation, we studied the relationship between nasalance and voice disorders by observing abnormal supraglottic movements and vocol cord gaps in phonation. SUBJECTS AND METHOD: There were 143 patients who complained of voice problems and showed abnormal false vocal cord movements under stroboscopy. In addition to the four previously described types of MTD (muscle tension dysphonia), we described two more types of MTD (V: false vocal cord contracted posteriorly, VI: false vocal cord dilated laterally). We measured the vocal cord gaps in phonation and analyzed nasalance. RESULTS: Among those groups showing the pattern of false vocal cord (MTD 1, 2, 4), the vocal cord gaps in phonation were increased and nasalance was significantly decreased in MTD types, III and IV, and showed a tendency to decrease in MTD types, II and V, compared to the normal group. CONCLUSION: The supraglottis has a tendency to contract as the vocal cord gap in phonation increases, and this movement reduces nasalance.