Useful Speech Task in the Perceptual Evaluation of Adductor Spasmodic Dysphonia

The purpose of the study was to determine which speech task is more useful in perceptual evaluation of adductor spasmodic dysphonia(ADSD). Pre-recorded sustained /a/ phonation and the sentences of 20 patients with ADSD and five normal control subjects were evaluated by trained listeners (1) to differentiate between ADSD and normal voice and (2) to judge the severity of ADSD with VAS. The results showed that the sentence task (sensitivity=1.0, specificity=1.0) was more useful in the diagnosis than sustained /a/ phonation task (sensitivity=.85, specificity=.93). The results of the acoustic analyses of the samp.es of sustained /a/ phonation demonstrated that the acoustic features of ‘frequency shift, phonatory break, and aperiodicity’ were observed only in the patients with moderate to severe ADSD. These results indicated that a sentence task is more sensitive in differentiating between the normal and the ADSD. If only vowel task is used in the evaluating procedure, false negative characteristic might be observed.ope