Nasometric assessment of hypernasality in children: optimalized speech material and normative values

Abstract

Objectives: (1) To define adequate speech material and normative data for Dutch children with a new Nasometer, the “NasalView System”. (2) To define the minimal amount of required speech tasks. Methods: 55 children (30 normal and 25 velo-pharyngeal insufficient), aged 4–11 are included. All children had to read or repeat two Dutch passages [one with a normal amount of nasal consonants (normal passage) and one with none (denasal passage)]. (1) Out of group means and standard deviations (S.D.) “pathological nasalance boundaries” [mean±2×S.D.], in combination with the sensitivity, specificity and positive predictive values for both passages, are computed. (2) With ANOVA all sentences within each passage are tested for significant differences in nasalance. Results: (1) The pathological boundaries are 28.6–41.4% (mean: 35.0) and 21.4–34.7% (mean: 28.1) for the normal and denasal passage, respectively. For the normal passage a sensitivity of 96%, a specificity of 93% and a positive predictive value of 92% is computed. For the denasal passage these parameters are 96%, 95% and 96%, respectively. (2) Within the normal passage only the third sentence is significantly different in nasalance, compared to the entire passage (31.2% vs. 35.0%). Within the denasal passage the second and fifth sentence are significantly different (23.8% and 24.8% vs. 28.1%). However, the individual non-significantly different sentences show a higher variation in nasalance compared to the entire passages.