Effect of Stimulus Length on Nasalance Scores

Abstract

Objective

Nasalance measures were compared for speech stimuli of four different lengths.

Design

The standard for comparison was a 44-syllable passage. The 44-syllable passage was compared to a 17-syllable passage, a 6-syllable sentence, and 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 dysfunction and 5 children without history of communication disorder.

Main outcome measure(s)

The main outcome measures were the nasalance scores associated with speech samples of different lengths.

Results

The results showed that comparable measures of nasalance can be obtained using stimuli as short as a six-syllable sentence. Both the 17-syllable and the 6-syllable stimulus achieved high criterion validity, indicating that stimuli of that length could be substituted for the longer 44-syllable passage. The two-syllable word, however, had significantly lower criterion validity and could not be used to obtain valid estimates of nasalance.

Conclusion

Valid assessment of nasalance can be achieved with speech samples as short as six syllables.