The Change of the Nasalance Score following Simulated Nasal Obstruction

인위적인 비폐색에 의한 비음치의 변화

Nasal obstruction due to nasal deformities, rhinitis, sinusitis, or nasal polyps etc. induces hyponasality, which can influence the articulation and/or phonation of patients. However few studies were done on the subjects. Therefore, this study was performed to establish the guideline that can be used in diagnosing the hyponasality. We analyzed the nasalance scores of 6 different sentences for 26 normal adults. We measured the nasalance scores before simulated nasal obstruction, after one nostril obstruction, and after both nostrils obstruction, while the subjects are reading roe nasal sentences(so-called, 'Mama' sentence, 'Mimi' sentence, and 'Nana' sentence) and three non-nasal sentences('Papa' sentence, 'Bibi' sentence, and 'Tatda' sentence). The change of nasalance score of six sentences were compared in three conditions, that is, without obstruction, with one nostril obstruction, and with both nostrils obstruction. The nasalance scores of one nostril obstruction and both nostrils obstruction were significantly lower than those of no obstruction. The mean nasalance scores of one nostril obstruction and both nostrils obstruction were lower than those of no obstruction by 10.93% and 48.88% in 'Mama' sentence, 3.72% and 5.76% in 'Papa' sentence, 12.28% nd 38.12% in 'Mimi' sentence, 7.28% and 12.96% in 'Bibi' sentence, 13.32% and 34.62% in 'Nana' sentence, 4.27% and 717% in 'Tatda' sentence, respectively. In both nostrils obstruction, the nasalance score of nasal sentences were decreased more than those of non-nasal sentences significantly. The result suggests that nasal sentences can be used as efficient stimuli in assessing the patients suspected of hyponasality. Eventhough non-nasal sentences also induced significant discrimination, the dynamic range was too small.