Normative data on nasalance scores for Farsi speaking children: Influence of age, gender and phonetic context

Background: Normative nasalance scores are essential for treatment and assessment purposes for clinicians. The purpose of the current study is to determine the normative data on nasalance scores for Farsi speaking children. Comparing to the obtained normative data, hypernasal or hyponasal speech (i.e. the higher or lower nasalance score) can be evaluated. Methods: Ninety-six Farsi speakers ranging from 4 years to 11 years old with typically developing speech were included in this study. Mean nasalance scores were obtained using the Universal Parameters System sentences with nasometer II (model 6450). The nasalance data was also analyzed for any gender, age and phonetic context dependence. Results: Normative nasalance values were determined, Nno differences were found for gender and age for the school-aged children. With an increasing in age, the nasalance score also increased in oral passages but not in nasal passages. Furthermore, amongst the nasalance scores there was a significant difference between these four categories of sentences: 7 sentences loaded with oral stop consonants, 5 sentences loaded with oral fricative consonants, 2 sentences loaded with oral affricatives and 3 sentences loaded with nasal consonants. Conclusions: The absence of age and gender differences led to a computation of an overall mean nasalance score for different types of phonetic context (Nasal, oral and oronasal). These normative nasalance data for Farsi speaking children will provide important reference information during speech assessments of children with velopharyngeal insufficiency.