SPRACHE STIMME GEHOR 22/2 (1998) 98-106
Abstract
We present the first results of a clinical study using Awan's [1,2] NasalView, a new instrument for apparative diagnostics of Rhinophonia. Like the KAY-Nasometer, the NasalView measures nasalance, the relative sound pressure level of the nasal signal in speech, expressed in percentages. NasalView requires a regular multimedia-PC and minimal additional hardware (headset and preamplifier). We examined 156 patients with operated cleft lip and palate in order to evaluate the effectiveness of computerised measurement of nasalance. For testing materials, a modified version of the Heidelberg Rhinophonia Assessment Form [27] was used. Statistical analysis revealed good agreement between clinical assessment and the measurements of NasalView. Using ROC-curves, we defined Cut-off points for the individual items of the Heidelberg Rhinophonia Assessment Form. On the basis of these Cut-offs, NasalView differentiated between speakers with normal resonance and speakers with mild to severe hypernasality with a sensitivity of 79.6% and a specificity of 71.1%, between normal and medium to severe hypernasality with a sensitivity of 81.7% and a specificity of 80.0%, and between normal and severe hypernasality with a sensitivity of 85.5% and a specificity of 91.0%. For five sentences without nasals, NasalView differentiated between patients with normal nasal resonance and patients with mild to severe hyernasality with a sensitivity of 74,0% and a specificity of 73.0% (Cut-off 28.5), between normal and medium to severe hypernasality with a sensitivity of 89,7% and a specificity of 73.0% (Cut-off 28.5), and between normal and severe hypernasality with a sensitivity of 91.1% and a specificity of 88.5 (Cut-off 32.0). Based on these results, we conclude that NasalView can help making the decision for velopharngyplasty as well as controlling operative success. Furthermore, it is of great value in speech therapy.