Optimizing stimulus length for clinical nasalance measures in Swedish

Standardized passages used for speech nasalance measures may be too long for clinical use with very young or non-compliant patients. The aim of this study was to establish whether nasalance scores from shorter sections of three Swedish speech stimuli were equivalent to those from their corresponding whole stimulus. Nasalance recordings for three Swedish speech stimuli (oral, nasal and oronasal) were obtained from 29 typically developing Swedish children (7-11 years). Cumulative sentence combinations were evaluated for equivalence to their respective whole passages according to two different criteria: one based on t-testing and the other on cumulative frequencies of score differences. Results showed that shorter sequences of sentences could be considered equivalent to the whole passage for the oral and nasal stimuli, provided that the sentences were sequenced in order of increasing difference from the whole stimulus score and that those sentences with scores significantly different from the whole passage score were not included.