Effect of stimulus length on nasalance scores

Objective: Nasalance measures were compared for speech stimuli of four diff erent lengths. Design: The standard for comparison was a 44-syllable passage. The 44-sylla ble passage was compared to a 17-syllable passage, a 6-syllable sentence, a nd a 2-syllable word. All stimuli were devoid of nasal consonants and were composed only of low pressure consonants and vowels. Setting: Academic and clinical craniofacial center. Subjects: The subjects were 20 children at risk for velopharyngeal dysfunct ion and 5 children without history of communication disorder. Main outcome measure(s): The main outcome measures were the nasalance score s associated with speech samples of different lengths. Results: The results showed that comparable measures of nasalance can be ob tained using stimuli as short as a six-syllable sentence, Both the 17-sylla ble and the 6-syllable stimulus achieved high criterion validity, indicatin g that stimuli of that length could be substituted for the longer 44-syllab le passage. The two-syllable word, however, had significantly lower criteri on validity and could not be used to obtain valid estimates of nasalance. Conclusion: Valid assessment of nasalance can be achieved with speech sampl es as short as six syllables.