The main purpose of the present acoustical study was to delineate further the changes in nasal resonance in childhood and young adulthood. An additional objective was to collect reference nasal resonance scores for normal Flemish-speaking children. Scores were recorded with a Nasometer while 33 children produced sounds and read three standard passages. We compared the nasal resonance data from the children with those of 58 adults that had been obtained in a previous study. Age had a significant effect on three sounds and two texts. The results indicated that young Flemish adults had higher nasal resonance scores than children, particularly when the reading stimuli included nasal consonants for which a co-ordinated opening and closing function of the velopharyngeal mechanism was required. These results reflect anatomical changes and differences in speech programming associated with growth.