Acoustic variations in adductor spasmodic dysphonia as a function of speech task

Acoustic phonatory events were identified in 14 women diagnosed with ADSD a nd compared to those of 14 women age-matched (+/-2 years) with no evidence of vocal pathology/dysfunction. The three acoustic parameters examined duri ng sustained vowel production and reading included phonatory breaks, aperio dicity and frequency shifts. Intra- and intermeasurer correlations showed h igh reliability for the measures. Findings indicated that those with ADSD p roduced a greater frequency of aberrant acoustic events than the controls d uring both tasks. For the group with ADSD, the amount and type of each even t also varied with utterance type. The sustained vowel sample produced by t hose with ADSD consisted of a greater percentage of aperiodic segments foll owed by phonatory breaks and frequency shifts. During reading, frequency sh ifts were the predominant acoustic event Followed by phonatory breaks and a periodicity. The advantage of segmenting the acoustic waveform into these m easures and the relevancy of examining intertask performances by those with ADSD is discussed.