Effects of age and gender in normal-speaking children on the nasality severity index: an objective multiparametric...

Since resonance disorders have a multidimensional nature and occur in several craniofacial pathologies, the aim of the present study was to determine the influence of age and gender in normal-speaking children without resonance disorders on an objective multiparametric index of hypernasality.

A total of 74 Flemish children (37 boys and 37 girls), aged 4-12 years, without resonance disorders were included. A Nasometer was used to obtain nasalance scores (1 phoneme, 2 reading passages). An aerodynamic value was calculated using maximum duration time, and the mirror-fogging test by Glatzel was applied to visualize nasality as measured by condensation. With the obtained results, a 'Nasality Severity Index' (NSI) was calculated.

A significant age effect was found, in which the NSI increased with increasing age (p < 0.001). No significant difference for the NSI was detected concerning gender (p > 0.05). Unfortunately, considerable standard deviations from the mean NSI were found.

Although a multiparametric index can form a more powerful approach in the assessment of and treatment planning for individuals with hypernasality, the present study revealed large interindividual differences in the current NSI. Therefore, adaptation of the current NSI is recommended, by which the influences of personal and environmental variables are taken into account.