Nasalance distance and ratio: Two new measures

Objectives: Mean nasalance in speakers with perceptually normal nasal reson ance can differ in magnitude considerably. In addition, categorizations of speech based on nasalance scores may not agree with perceptual judgments, T o overcome this limitation, we evaluated two new simple measures derived fr om mean nasalance data: the nasalance distance (range between maximum and m inimum nasalance) and the nasalance ratio (minimum nasalance divided by max imum nasalance). Setting: Department of Oral and Maxillofacial Surgery, University of Techno logy, Munich, Germany. Subjects: The sample consisted of 133 cleft lip and palate patients with no rmal nasal resonance or varying degrees of hypernasality. Procedures: Oral and nasal acoustic measurements were made using the NasalV iew system. Nasalance distance and nasalance ratio were calculated for five nonnasal and three nasal sentences from the modified Heidelberg Rhinophoni a Assessment Form. Results: Optimum cutoffs were derived from Receiver-Operating Characteristi cs. Results for the sentence stimuli ranged from 64.4% to 89.6% sensitivity and from 91.2% to 94.1% specificity. When the analysis was limited to only one nonnasal and one nasal sentence, results ranged from 79.7% to 87.5% se nsitivity and from 88.2% to 97.1% specificity. Conclusions: We conclude that the two new measurements are valuable in rout ine clinical examinations. Nasalance distance and ratio derived from senten ce stimuli are two useful and easily applicable measures that can be used t o supplement the nasalance mean value.